{"trustable":true,"prependHtml":"\u003cstyle type\u003d\u0027text/css\u0027\u003e.content-description h4 {\n font-size: 1.4em;\n border-bottom: 1px solid #eee;\n line-height: 1.225;\n padding-bottom: 0.3em;\n padding-top: 0.5em;\n font-weight: 700;\n}.content-description img {\n max-width: 100%;\n height: auto;\n}\u003c/style\u003e","sections":[{"title":"","value":{"format":"HTML","content":"\u003cdiv class\u003d\"content-description screen\"\u003e\n\u003cdiv\u003e\u003cp\u003eThousands Islands is a group of beautiful islands located in the Java Sea.\nIt consists of \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/7b60d7c68d7ec066966b2e5a535229a8?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:2.064ex; height:2.176ex;\" alt\u003d\"N\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~N~\u003c/span\u003e\u003c/span\u003e islands, numbered from \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/fc9653f00347ae032c0bb3370a2c7a76?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"0\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~0~\u003c/span\u003e\u003c/span\u003e to \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/fd8b3536ed085708a0178c8e31f8cf22?v\u003d1715245171\" style\u003d\"vertical-align: -0.505ex; width:6.066ex; height:2.343ex;\" alt\u003d\"N-1\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~N-1~\u003c/span\u003e\u003c/span\u003e.\u003c/p\u003e\n\u003cp\u003eThere are \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/09364895aecdedfd8cb6f510534a1e89?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:2.442ex; height:2.176ex;\" alt\u003d\"M\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~M~\u003c/span\u003e\u003c/span\u003e canoes, numbered from \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/fc9653f00347ae032c0bb3370a2c7a76?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"0\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~0~\u003c/span\u003e\u003c/span\u003e to \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/3797afad61dcb719af9b68f5c4065c93?v\u003d1715245171\" style\u003d\"vertical-align: -0.505ex; width:6.445ex; height:2.343ex;\" alt\u003d\"M-1\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~M-1~\u003c/span\u003e\u003c/span\u003e, that can be used to sail between islands.\nFor each \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/a4e1016e68b8319096078a41bff14fe0?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:0.802ex; height:2.176ex;\" alt\u003d\"i\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~i~\u003c/span\u003e\u003c/span\u003e such that \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/524d7a199ebc15d90e67c94707acf657?v\u003d1715245171\" style\u003d\"vertical-align: -0.505ex; width:14.607ex; height:2.343ex;\" alt\u003d\"0 \\le i \\le M-1\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~0 \\le i \\le M-1~\u003c/span\u003e\u003c/span\u003e, canoe \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/a4e1016e68b8319096078a41bff14fe0?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:0.802ex; height:2.176ex;\" alt\u003d\"i\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~i~\u003c/span\u003e\u003c/span\u003e can be docked either at island \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/bd49c4d50715c82953012aa0a373c20b?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:3.879ex; height:2.843ex;\" alt\u003d\"U[i]\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~U[i]~\u003c/span\u003e\u003c/span\u003e or \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/d8638a6a5caab53d915871d2c67a6a94?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:3.883ex; height:2.843ex;\" alt\u003d\"V[i]\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~V[i]~\u003c/span\u003e\u003c/span\u003e, and can be used to sail between islands \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/bd49c4d50715c82953012aa0a373c20b?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:3.879ex; height:2.843ex;\" alt\u003d\"U[i]\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~U[i]~\u003c/span\u003e\u003c/span\u003e and \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/d8638a6a5caab53d915871d2c67a6a94?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:3.883ex; height:2.843ex;\" alt\u003d\"V[i]\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~V[i]~\u003c/span\u003e\u003c/span\u003e.\nSpecifically, when the canoe is docked at island \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/bd49c4d50715c82953012aa0a373c20b?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:3.879ex; height:2.843ex;\" alt\u003d\"U[i]\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~U[i]~\u003c/span\u003e\u003c/span\u003e, it can be used to sail from island \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/bd49c4d50715c82953012aa0a373c20b?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:3.879ex; height:2.843ex;\" alt\u003d\"U[i]\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~U[i]~\u003c/span\u003e\u003c/span\u003e to island \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/d8638a6a5caab53d915871d2c67a6a94?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:3.883ex; height:2.843ex;\" alt\u003d\"V[i]\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~V[i]~\u003c/span\u003e\u003c/span\u003e, after which the canoe becomes docked at island \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/d8638a6a5caab53d915871d2c67a6a94?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:3.883ex; height:2.843ex;\" alt\u003d\"V[i]\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~V[i]~\u003c/span\u003e\u003c/span\u003e.\nSimilarly, when the canoe is docked at island \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/d8638a6a5caab53d915871d2c67a6a94?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:3.883ex; height:2.843ex;\" alt\u003d\"V[i]\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~V[i]~\u003c/span\u003e\u003c/span\u003e, it can be used to sail from island \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/d8638a6a5caab53d915871d2c67a6a94?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:3.883ex; height:2.843ex;\" alt\u003d\"V[i]\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~V[i]~\u003c/span\u003e\u003c/span\u003e to island \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/bd49c4d50715c82953012aa0a373c20b?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:3.879ex; height:2.843ex;\" alt\u003d\"U[i]\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~U[i]~\u003c/span\u003e\u003c/span\u003e, after which the canoe becomes docked at island \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/bd49c4d50715c82953012aa0a373c20b?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:3.879ex; height:2.843ex;\" alt\u003d\"U[i]\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~U[i]~\u003c/span\u003e\u003c/span\u003e.\nInitially, the canoe is docked at island \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/bd49c4d50715c82953012aa0a373c20b?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:3.879ex; height:2.843ex;\" alt\u003d\"U[i]\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~U[i]~\u003c/span\u003e\u003c/span\u003e.\nIt is possible that multiple canoes can be used to sail between the same pair of islands.\nIt is also possible that multiple canoes are docked at the same island.\u003c/p\u003e\n\u003cp\u003eFor safety reasons, a canoe needs to be maintained after every time it is sailed, which forbids the same canoe to be sailed two times in a row.\nThat is, after using some canoe \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/a4e1016e68b8319096078a41bff14fe0?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:0.802ex; height:2.176ex;\" alt\u003d\"i\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~i~\u003c/span\u003e\u003c/span\u003e, another canoe must be used before canoe \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/a4e1016e68b8319096078a41bff14fe0?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:0.802ex; height:2.176ex;\" alt\u003d\"i\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~i~\u003c/span\u003e\u003c/span\u003e can be used again.\u003c/p\u003e\n\u003cp\u003eBu Dengklek wants to plan a journey through some of the islands.\nHer journey is \u003cstrong\u003evalid\u003c/strong\u003e if and only if the following conditions are satisfied.\u003c/p\u003e\n\u003cul\u003e\n\u003cli\u003eShe starts and ends her journey at island \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/fc9653f00347ae032c0bb3370a2c7a76?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"0\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~0~\u003c/span\u003e\u003c/span\u003e.\u003c/li\u003e\n\u003cli\u003eShe visits at least one island other than island \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/fc9653f00347ae032c0bb3370a2c7a76?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"0\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~0~\u003c/span\u003e\u003c/span\u003e.\u003c/li\u003e\n\u003cli\u003eAfter the journey ends, each canoe is docked at the same island as it was before the journey.\nI.e., canoe \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/a4e1016e68b8319096078a41bff14fe0?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:0.802ex; height:2.176ex;\" alt\u003d\"i\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~i~\u003c/span\u003e\u003c/span\u003e, for each \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/a4e1016e68b8319096078a41bff14fe0?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:0.802ex; height:2.176ex;\" alt\u003d\"i\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~i~\u003c/span\u003e\u003c/span\u003e such that \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/524d7a199ebc15d90e67c94707acf657?v\u003d1715245171\" style\u003d\"vertical-align: -0.505ex; width:14.607ex; height:2.343ex;\" alt\u003d\"0 \\le i \\le M-1\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~0 \\le i \\le M-1~\u003c/span\u003e\u003c/span\u003e, must be docked at island \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/bd49c4d50715c82953012aa0a373c20b?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:3.879ex; height:2.843ex;\" alt\u003d\"U[i]\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~U[i]~\u003c/span\u003e\u003c/span\u003e.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eHelp Bu Dengklek find any valid journey involving sailing at most \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/aadef7fb3f44313bef8c7e299f932c7b?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:8.912ex; height:2.176ex;\" alt\u003d\"2\\,000\\,000\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~2\\,000\\,000~\u003c/span\u003e\u003c/span\u003e times, or determine that no such valid journey exists.\nIt can be proven that under the constraints specified in this task (see Constraints section), if a valid journey exists, there also exists a valid journey that does not involve sailing more than \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/aadef7fb3f44313bef8c7e299f932c7b?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:8.912ex; height:2.176ex;\" alt\u003d\"2\\,000\\,000\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~2\\,000\\,000~\u003c/span\u003e\u003c/span\u003e times.\u003c/p\u003e\n\u003ch4\u003eImplementation Details\u003c/h4\u003e\n\u003cp\u003eYou should implement the following procedure:\u003c/p\u003e\n\u003cdiv class\u003d\"codehilite\"\u003e\u003cpre\u003e\u003cspan\u003e\u003c/span\u003e\u003ccode\u003e\u003cspan class\u003d\"n\"\u003estd\u003c/span\u003e\u003cspan class\u003d\"o\"\u003e::\u003c/span\u003e\u003cspan class\u003d\"n\"\u003evariant\u003c/span\u003e\u003cspan class\u003d\"o\"\u003e\u0026lt;\u003c/span\u003e\u003cspan class\u003d\"kt\"\u003ebool\u003c/span\u003e\u003cspan class\u003d\"p\"\u003e,\u003c/span\u003e \u003cspan class\u003d\"n\"\u003estd\u003c/span\u003e\u003cspan class\u003d\"o\"\u003e::\u003c/span\u003e\u003cspan class\u003d\"n\"\u003evector\u003c/span\u003e\u003cspan class\u003d\"o\"\u003e\u0026lt;\u003c/span\u003e\u003cspan class\u003d\"kt\"\u003eint\u003c/span\u003e\u003cspan class\u003d\"o\"\u003e\u0026gt;\u0026gt;\u003c/span\u003e \u003cspan class\u003d\"n\"\u003efind_journey\u003c/span\u003e\u003cspan class\u003d\"p\"\u003e(\u003c/span\u003e\u003cspan class\u003d\"kt\"\u003eint\u003c/span\u003e \u003cspan class\u003d\"n\"\u003eN\u003c/span\u003e\u003cspan class\u003d\"p\"\u003e,\u003c/span\u003e \u003cspan class\u003d\"kt\"\u003eint\u003c/span\u003e \u003cspan class\u003d\"n\"\u003eM\u003c/span\u003e\u003cspan class\u003d\"p\"\u003e,\u003c/span\u003e \u003cspan class\u003d\"n\"\u003estd\u003c/span\u003e\u003cspan class\u003d\"o\"\u003e::\u003c/span\u003e\u003cspan class\u003d\"n\"\u003evector\u003c/span\u003e\u003cspan class\u003d\"o\"\u003e\u0026lt;\u003c/span\u003e\u003cspan class\u003d\"kt\"\u003eint\u003c/span\u003e\u003cspan class\u003d\"o\"\u003e\u0026gt;\u003c/span\u003e \u003cspan class\u003d\"n\"\u003eU\u003c/span\u003e\u003cspan class\u003d\"p\"\u003e,\u003c/span\u003e \u003cspan class\u003d\"n\"\u003estd\u003c/span\u003e\u003cspan class\u003d\"o\"\u003e::\u003c/span\u003e\u003cspan class\u003d\"n\"\u003evector\u003c/span\u003e\u003cspan class\u003d\"o\"\u003e\u0026lt;\u003c/span\u003e\u003cspan class\u003d\"kt\"\u003eint\u003c/span\u003e\u003cspan class\u003d\"o\"\u003e\u0026gt;\u003c/span\u003e \u003cspan class\u003d\"n\"\u003eV\u003c/span\u003e\u003cspan class\u003d\"p\"\u003e)\u003c/span\u003e\n\u003c/code\u003e\u003c/pre\u003e\u003c/div\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/7b60d7c68d7ec066966b2e5a535229a8?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:2.064ex; height:2.176ex;\" alt\u003d\"N\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~N~\u003c/span\u003e\u003c/span\u003e: the number of islands.\u003c/li\u003e\n\u003cli\u003e\u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/09364895aecdedfd8cb6f510534a1e89?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:2.442ex; height:2.176ex;\" alt\u003d\"M\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~M~\u003c/span\u003e\u003c/span\u003e: the number of canoes.\u003c/li\u003e\n\u003cli\u003e\u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/7bc243c2346bdca2192a74afd39c85ed?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.783ex; height:2.176ex;\" alt\u003d\"U\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~U~\u003c/span\u003e\u003c/span\u003e, \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/f5c1e4c6dfbee4eee20f25b9534a8495?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.787ex; height:2.176ex;\" alt\u003d\"V\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~V~\u003c/span\u003e\u003c/span\u003e: arrays of length \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/09364895aecdedfd8cb6f510534a1e89?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:2.442ex; height:2.176ex;\" alt\u003d\"M\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~M~\u003c/span\u003e\u003c/span\u003e describing the canoes.\u003c/li\u003e\n\u003cli\u003eThis procedure should return either a boolean or an array of integers.\u003cul\u003e\n\u003cli\u003eIf no valid journey exists, the procedure should return \u003ccode\u003efalse\u003c/code\u003e.\u003c/li\u003e\n\u003cli\u003eIf a valid journey exists, you have two options:\u003cul\u003e\n\u003cli\u003eTo be awarded the full score, the procedure should return an array of at most \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/aadef7fb3f44313bef8c7e299f932c7b?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:8.912ex; height:2.176ex;\" alt\u003d\"2\\,000\\,000\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~2\\,000\\,000~\u003c/span\u003e\u003c/span\u003e integers representing a valid journey. More precisely, the elements of this array should be the numbers of the canoes that are used in the journey (in the order they are used).\u003c/li\u003e\n\u003cli\u003eTo be awarded a partial score, the procedure should return \u003ccode\u003etrue\u003c/code\u003e, an array of more than \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/aadef7fb3f44313bef8c7e299f932c7b?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:8.912ex; height:2.176ex;\" alt\u003d\"2\\,000\\,000\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~2\\,000\\,000~\u003c/span\u003e\u003c/span\u003e integers, or an array of integers not describing a valid journey. (See the Subtasks section for more details.)\u003c/li\u003e\n\u003c/ul\u003e\n\u003c/li\u003e\n\u003c/ul\u003e\n\u003c/li\u003e\n\u003cli\u003eThis procedure is called exactly once.\u003c/li\u003e\n\u003c/ul\u003e\n\u003ch4\u003eExamples\u003c/h4\u003e\n\u003ch5\u003eExample 1\u003c/h5\u003e\n\u003cp\u003eConsider the following call:\u003c/p\u003e\n\u003cdiv class\u003d\"codehilite\"\u003e\u003cpre\u003e\u003cspan\u003e\u003c/span\u003e\u003ccode\u003e\u003cspan class\u003d\"n\"\u003efind_journey\u003c/span\u003e\u003cspan class\u003d\"p\"\u003e(\u003c/span\u003e\u003cspan class\u003d\"mi\"\u003e4\u003c/span\u003e\u003cspan class\u003d\"p\"\u003e,\u003c/span\u003e \u003cspan class\u003d\"mi\"\u003e5\u003c/span\u003e\u003cspan class\u003d\"p\"\u003e,\u003c/span\u003e \u003cspan class\u003d\"p\"\u003e{\u003c/span\u003e\u003cspan class\u003d\"mi\"\u003e0\u003c/span\u003e\u003cspan class\u003d\"p\"\u003e,\u003c/span\u003e \u003cspan class\u003d\"mi\"\u003e1\u003c/span\u003e\u003cspan class\u003d\"p\"\u003e,\u003c/span\u003e \u003cspan class\u003d\"mi\"\u003e2\u003c/span\u003e\u003cspan class\u003d\"p\"\u003e,\u003c/span\u003e \u003cspan class\u003d\"mi\"\u003e0\u003c/span\u003e\u003cspan class\u003d\"p\"\u003e,\u003c/span\u003e \u003cspan class\u003d\"mi\"\u003e3\u003c/span\u003e\u003cspan class\u003d\"p\"\u003e},\u003c/span\u003e \u003cspan class\u003d\"p\"\u003e{\u003c/span\u003e\u003cspan class\u003d\"mi\"\u003e1\u003c/span\u003e\u003cspan class\u003d\"p\"\u003e,\u003c/span\u003e \u003cspan class\u003d\"mi\"\u003e2\u003c/span\u003e\u003cspan class\u003d\"p\"\u003e,\u003c/span\u003e \u003cspan class\u003d\"mi\"\u003e3\u003c/span\u003e\u003cspan class\u003d\"p\"\u003e,\u003c/span\u003e \u003cspan class\u003d\"mi\"\u003e3\u003c/span\u003e\u003cspan class\u003d\"p\"\u003e,\u003c/span\u003e \u003cspan class\u003d\"mi\"\u003e1\u003c/span\u003e\u003cspan class\u003d\"p\"\u003e})\u003c/span\u003e\n\u003c/code\u003e\u003c/pre\u003e\u003c/div\u003e\n\u003cp\u003eThe islands and canoes are shown in the picture below.\u003c/p\u003e\n\u003cdiv style\u003d\"text-align:center;\"\u003e\u003cimg src\u003d\"CDN_BASE_URL/39cd9357ce35dd9b9d8d14960afa7723?v\u003d1715245171\" alt\u003e\u003c/div\u003e\u003cp\u003eOne possible valid journey is as follows.\nBu Dengklek first sails canoes \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/fc9653f00347ae032c0bb3370a2c7a76?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"0\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~0~\u003c/span\u003e\u003c/span\u003e, \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/dc15aebf4fa2f4039e7e91a157d4b279?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"1\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~1~\u003c/span\u003e\u003c/span\u003e, \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/edff4a53ceab26bbeb9fa3434bd9765d?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"2\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~2~\u003c/span\u003e\u003c/span\u003e, and \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/acf1b79c1849c49564c7ac0004e5c5e3?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"4\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~4~\u003c/span\u003e\u003c/span\u003e in that order.\nAs a result, she is at island \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/dc15aebf4fa2f4039e7e91a157d4b279?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"1\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~1~\u003c/span\u003e\u003c/span\u003e.\nAfter that, Bu Dengklek can sail canoe \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/fc9653f00347ae032c0bb3370a2c7a76?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"0\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~0~\u003c/span\u003e\u003c/span\u003e again as it is currently docked at island \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/dc15aebf4fa2f4039e7e91a157d4b279?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"1\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~1~\u003c/span\u003e\u003c/span\u003e and the last canoe she used is not canoe \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/fc9653f00347ae032c0bb3370a2c7a76?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"0\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~0~\u003c/span\u003e\u003c/span\u003e.\nAfter sailing canoe \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/fc9653f00347ae032c0bb3370a2c7a76?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"0\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~0~\u003c/span\u003e\u003c/span\u003e again, Bu Dengklek is now at island \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/fc9653f00347ae032c0bb3370a2c7a76?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"0\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~0~\u003c/span\u003e\u003c/span\u003e.\nHowever, canoes \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/dc15aebf4fa2f4039e7e91a157d4b279?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"1\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~1~\u003c/span\u003e\u003c/span\u003e, \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/edff4a53ceab26bbeb9fa3434bd9765d?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"2\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~2~\u003c/span\u003e\u003c/span\u003e and \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/acf1b79c1849c49564c7ac0004e5c5e3?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"4\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~4~\u003c/span\u003e\u003c/span\u003e are not docked at the same islands as they were before the journey.\nBu Dengklek then continues her journey by sailing canoes \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/86748ce269b76185f219ba13eeede716?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"3\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~3~\u003c/span\u003e\u003c/span\u003e, \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/edff4a53ceab26bbeb9fa3434bd9765d?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"2\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~2~\u003c/span\u003e\u003c/span\u003e, \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/dc15aebf4fa2f4039e7e91a157d4b279?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"1\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~1~\u003c/span\u003e\u003c/span\u003e, \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/acf1b79c1849c49564c7ac0004e5c5e3?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"4\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~4~\u003c/span\u003e\u003c/span\u003e, and \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/86748ce269b76185f219ba13eeede716?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"3\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~3~\u003c/span\u003e\u003c/span\u003e again.\nBu Dengklek is back at island \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/fc9653f00347ae032c0bb3370a2c7a76?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"0\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~0~\u003c/span\u003e\u003c/span\u003e and all the canoes are docked at the same islands as before the journey.\u003c/p\u003e\n\u003cp\u003eTherefore, the returned value \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/8a0c2179dcfa8912f7d0d10a95162d37?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:22.224ex; height:2.843ex;\" alt\u003d\"[0, 1, 2, 4, 0, 3, 2, 1, 4, 3]\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~[0, 1, 2, 4, 0, 3, 2, 1, 4, 3]~\u003c/span\u003e\u003c/span\u003e represents a valid journey.\u003c/p\u003e\n\u003ch5\u003eExample 2\u003c/h5\u003e\n\u003cp\u003eConsider the following call:\u003c/p\u003e\n\u003cdiv class\u003d\"codehilite\"\u003e\u003cpre\u003e\u003cspan\u003e\u003c/span\u003e\u003ccode\u003e\u003cspan class\u003d\"n\"\u003efind_journey\u003c/span\u003e\u003cspan class\u003d\"p\"\u003e(\u003c/span\u003e\u003cspan class\u003d\"mi\"\u003e2\u003c/span\u003e\u003cspan class\u003d\"p\"\u003e,\u003c/span\u003e \u003cspan class\u003d\"mi\"\u003e3\u003c/span\u003e\u003cspan class\u003d\"p\"\u003e,\u003c/span\u003e \u003cspan class\u003d\"p\"\u003e{\u003c/span\u003e\u003cspan class\u003d\"mi\"\u003e0\u003c/span\u003e\u003cspan class\u003d\"p\"\u003e,\u003c/span\u003e \u003cspan class\u003d\"mi\"\u003e1\u003c/span\u003e\u003cspan class\u003d\"p\"\u003e,\u003c/span\u003e \u003cspan class\u003d\"mi\"\u003e1\u003c/span\u003e\u003cspan class\u003d\"p\"\u003e},\u003c/span\u003e \u003cspan class\u003d\"p\"\u003e{\u003c/span\u003e\u003cspan class\u003d\"mi\"\u003e1\u003c/span\u003e\u003cspan class\u003d\"p\"\u003e,\u003c/span\u003e \u003cspan class\u003d\"mi\"\u003e0\u003c/span\u003e\u003cspan class\u003d\"p\"\u003e,\u003c/span\u003e \u003cspan class\u003d\"mi\"\u003e0\u003c/span\u003e\u003cspan class\u003d\"p\"\u003e})\u003c/span\u003e\n\u003c/code\u003e\u003c/pre\u003e\u003c/div\u003e\n\u003cp\u003eThe islands and canoes are shown in the picture below.\u003c/p\u003e\n\u003cdiv style\u003d\"text-align:center;\"\u003e\u003cimg src\u003d\"CDN_BASE_URL/17a5d25d4a0485cb8cee0b8920aeb4b3?v\u003d1715245171\" alt\u003e\u003c/div\u003e\u003cp\u003eBu Dengklek can only start by sailing canoe \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/fc9653f00347ae032c0bb3370a2c7a76?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"0\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~0~\u003c/span\u003e\u003c/span\u003e, after which she can sail either canoe \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/dc15aebf4fa2f4039e7e91a157d4b279?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"1\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~1~\u003c/span\u003e\u003c/span\u003e or \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/edff4a53ceab26bbeb9fa3434bd9765d?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"2\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~2~\u003c/span\u003e\u003c/span\u003e.\nNote that she cannot sail canoe \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/fc9653f00347ae032c0bb3370a2c7a76?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"0\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~0~\u003c/span\u003e\u003c/span\u003e twice in a row.\nIn both cases, Bu Dengklek is back at island \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/fc9653f00347ae032c0bb3370a2c7a76?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"0\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~0~\u003c/span\u003e\u003c/span\u003e.\nHowever, the canoes are not docked at the same islands as they were before the journey, and Bu Dengklek cannot sail any canoe afterwards, as the only canoe docked at island \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/fc9653f00347ae032c0bb3370a2c7a76?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"0\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~0~\u003c/span\u003e\u003c/span\u003e is the one she has just used.\nAs there is no valid journey, the procedure should return \u003ccode\u003efalse\u003c/code\u003e.\u003c/p\u003e\n\u003ch4\u003eConstraints\u003c/h4\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/aa047a33cd29ef1943c7e6c8304a55a0?v\u003d1715245171\" style\u003d\"vertical-align: -0.505ex; width:16.785ex; height:2.343ex;\" alt\u003d\"2 \\le N \\le 100\\,000\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~2 \\le N \\le 100\\,000~\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\n\u003cli\u003e\u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/b955ea3d3ba97f893fb9a05e841ea02a?v\u003d1715245171\" style\u003d\"vertical-align: -0.505ex; width:17.164ex; height:2.343ex;\" alt\u003d\"1 \\le M \\le 200\\,000\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~1 \\le M \\le 200\\,000~\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\n\u003cli\u003e\u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/7dbe4bcdf9b93a3bae63f0d39e0fc190?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:17.305ex; height:2.843ex;\" alt\u003d\"0 \\le U[i] \\le N-1\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~0 \\le U[i] \\le N-1~\u003c/span\u003e\u003c/span\u003e and \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/ed3265bda10c6a0574cf2c6faa10e9f3?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:17.309ex; height:2.843ex;\" alt\u003d\"0 \\le V[i] \\le N-1\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~0 \\le V[i] \\le N-1~\u003c/span\u003e\u003c/span\u003e (for each \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/a4e1016e68b8319096078a41bff14fe0?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:0.802ex; height:2.176ex;\" alt\u003d\"i\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~i~\u003c/span\u003e\u003c/span\u003e such that \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/524d7a199ebc15d90e67c94707acf657?v\u003d1715245171\" style\u003d\"vertical-align: -0.505ex; width:14.607ex; height:2.343ex;\" alt\u003d\"0 \\le i \\le M-1\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~0 \\le i \\le M-1~\u003c/span\u003e\u003c/span\u003e)\u003c/li\u003e\n\u003cli\u003e\u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/66c7ef6cbecad0dba0844ba0c3c04631?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:10.861ex; height:2.843ex;\" alt\u003d\"U[i] \\ne V[i]\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~U[i] \\ne V[i]~\u003c/span\u003e\u003c/span\u003e (for each \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/a4e1016e68b8319096078a41bff14fe0?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:0.802ex; height:2.176ex;\" alt\u003d\"i\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~i~\u003c/span\u003e\u003c/span\u003e such that \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/524d7a199ebc15d90e67c94707acf657?v\u003d1715245171\" style\u003d\"vertical-align: -0.505ex; width:14.607ex; height:2.343ex;\" alt\u003d\"0 \\le i \\le M-1\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~0 \\le i \\le M-1~\u003c/span\u003e\u003c/span\u003e)\u003c/li\u003e\n\u003c/ul\u003e\n\u003ch4\u003eSubtasks\u003c/h4\u003e\n\u003col\u003e\n\u003cli\u003e(5 points) \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/63144ac0d6f71d4f0c9b78be526ae5ca?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:6.325ex; height:2.176ex;\" alt\u003d\"N \u003d 2\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~N \u003d 2~\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\n\u003cli\u003e(5 points) \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/7dde10943c94fd1b3835798f9e573347?v\u003d1715245171\" style\u003d\"vertical-align: -0.505ex; width:8.65ex; height:2.343ex;\" alt\u003d\"N \\le 400\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~N \\le 400~\u003c/span\u003e\u003c/span\u003e.\nFor each pair of distinct islands \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/c5a1000106524b99ffb20096d04970b1?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.33ex; height:1.676ex;\" alt\u003d\"x\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~x~\u003c/span\u003e\u003c/span\u003e and \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/0e8f621bd8562db91042eb6f9f4e6dd4?v\u003d1715245171\" style\u003d\"vertical-align: -0.671ex; width:1.155ex; height:2.009ex;\" alt\u003d\"y\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~y~\u003c/span\u003e\u003c/span\u003e \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/51bc4188a14b98f976e60d919fa50b90?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:20.819ex; height:2.843ex;\" alt\u003d\"(0 \\le x \u003c y \\le N-1)\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~(0 \\le x \u0026lt; y \\le N-1)~\u003c/span\u003e\u003c/span\u003e, there are exactly two canoes that can be used to sail between them.\nOne of them is docked at island \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/c5a1000106524b99ffb20096d04970b1?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.33ex; height:1.676ex;\" alt\u003d\"x\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~x~\u003c/span\u003e\u003c/span\u003e, and the other one is docked at island \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/0e8f621bd8562db91042eb6f9f4e6dd4?v\u003d1715245171\" style\u003d\"vertical-align: -0.671ex; width:1.155ex; height:2.009ex;\" alt\u003d\"y\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~y~\u003c/span\u003e\u003c/span\u003e.\u003c/li\u003e\n\u003cli\u003e(21 points) \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/9de00adf68a10dbafee8f35e219c650b?v\u003d1715245171\" style\u003d\"vertical-align: -0.505ex; width:10.199ex; height:2.343ex;\" alt\u003d\"N \\le 1\\,000\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~N \\le 1\\,000~\u003c/span\u003e\u003c/span\u003e, \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/09364895aecdedfd8cb6f510534a1e89?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:2.442ex; height:2.176ex;\" alt\u003d\"M\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~M~\u003c/span\u003e\u003c/span\u003e is even, and for each \u003cstrong\u003eeven\u003c/strong\u003e \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/a4e1016e68b8319096078a41bff14fe0?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:0.802ex; height:2.176ex;\" alt\u003d\"i\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~i~\u003c/span\u003e\u003c/span\u003e such that \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/524d7a199ebc15d90e67c94707acf657?v\u003d1715245171\" style\u003d\"vertical-align: -0.505ex; width:14.607ex; height:2.343ex;\" alt\u003d\"0 \\le i \\le M-1\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~0 \\le i \\le M-1~\u003c/span\u003e\u003c/span\u003e, canoes \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/a4e1016e68b8319096078a41bff14fe0?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:0.802ex; height:2.176ex;\" alt\u003d\"i\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~i~\u003c/span\u003e\u003c/span\u003e and \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/cc2bcc2c55ce63f71474bdd25445dabc?v\u003d1715245171\" style\u003d\"vertical-align: -0.505ex; width:4.805ex; height:2.343ex;\" alt\u003d\"i+1\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~i+1~\u003c/span\u003e\u003c/span\u003e can both be used to sail between islands \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/bd49c4d50715c82953012aa0a373c20b?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:3.879ex; height:2.843ex;\" alt\u003d\"U[i]\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~U[i]~\u003c/span\u003e\u003c/span\u003e and \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/d8638a6a5caab53d915871d2c67a6a94?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:3.883ex; height:2.843ex;\" alt\u003d\"V[i]\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~V[i]~\u003c/span\u003e\u003c/span\u003e.\nCanoe \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/a4e1016e68b8319096078a41bff14fe0?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:0.802ex; height:2.176ex;\" alt\u003d\"i\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~i~\u003c/span\u003e\u003c/span\u003e is initially docked at island \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/bd49c4d50715c82953012aa0a373c20b?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:3.879ex; height:2.843ex;\" alt\u003d\"U[i]\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~U[i]~\u003c/span\u003e\u003c/span\u003e and canoe \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/cc2bcc2c55ce63f71474bdd25445dabc?v\u003d1715245171\" style\u003d\"vertical-align: -0.505ex; width:4.805ex; height:2.343ex;\" alt\u003d\"i+1\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~i+1~\u003c/span\u003e\u003c/span\u003e is initially docked at island \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/d8638a6a5caab53d915871d2c67a6a94?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:3.883ex; height:2.843ex;\" alt\u003d\"V[i]\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~V[i]~\u003c/span\u003e\u003c/span\u003e.\nFormally, \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/3a1f0b7b8a7fb47af645a08b7da2587e?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:14.863ex; height:2.843ex;\" alt\u003d\"U[i] \u003d V[i+1]\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~U[i] \u003d V[i+1]~\u003c/span\u003e\u003c/span\u003e and \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/b480176650251cec4e44b8b3755aa39c?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:14.863ex; height:2.843ex;\" alt\u003d\"V[i] \u003d U[i+1]\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~V[i] \u003d U[i+1]~\u003c/span\u003e\u003c/span\u003e.\u003c/li\u003e\n\u003cli\u003e(24 points) \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/9de00adf68a10dbafee8f35e219c650b?v\u003d1715245171\" style\u003d\"vertical-align: -0.505ex; width:10.199ex; height:2.343ex;\" alt\u003d\"N \\le 1\\,000\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~N \\le 1\\,000~\u003c/span\u003e\u003c/span\u003e, \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/09364895aecdedfd8cb6f510534a1e89?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:2.442ex; height:2.176ex;\" alt\u003d\"M\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~M~\u003c/span\u003e\u003c/span\u003e is even, and for each \u003cstrong\u003eeven\u003c/strong\u003e \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/a4e1016e68b8319096078a41bff14fe0?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:0.802ex; height:2.176ex;\" alt\u003d\"i\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~i~\u003c/span\u003e\u003c/span\u003e such that \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/524d7a199ebc15d90e67c94707acf657?v\u003d1715245171\" style\u003d\"vertical-align: -0.505ex; width:14.607ex; height:2.343ex;\" alt\u003d\"0 \\le i \\le M-1\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~0 \\le i \\le M-1~\u003c/span\u003e\u003c/span\u003e, canoes \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/a4e1016e68b8319096078a41bff14fe0?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:0.802ex; height:2.176ex;\" alt\u003d\"i\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~i~\u003c/span\u003e\u003c/span\u003e and \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/cc2bcc2c55ce63f71474bdd25445dabc?v\u003d1715245171\" style\u003d\"vertical-align: -0.505ex; width:4.805ex; height:2.343ex;\" alt\u003d\"i+1\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~i+1~\u003c/span\u003e\u003c/span\u003e can both be used to sail between islands \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/bd49c4d50715c82953012aa0a373c20b?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:3.879ex; height:2.843ex;\" alt\u003d\"U[i]\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~U[i]~\u003c/span\u003e\u003c/span\u003e and \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/d8638a6a5caab53d915871d2c67a6a94?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:3.883ex; height:2.843ex;\" alt\u003d\"V[i]\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~V[i]~\u003c/span\u003e\u003c/span\u003e.\nBoth canoes are initially docked at island \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/bd49c4d50715c82953012aa0a373c20b?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:3.879ex; height:2.843ex;\" alt\u003d\"U[i]\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~U[i]~\u003c/span\u003e\u003c/span\u003e.\nFormally, \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/d13c73181bff3a38566e79e26602d388?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:14.859ex; height:2.843ex;\" alt\u003d\"U[i] \u003d U[i+1]\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~U[i] \u003d U[i+1]~\u003c/span\u003e\u003c/span\u003e and \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/6eaf304340b5a5c6f9ee5427bc3c913d?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:14.868ex; height:2.843ex;\" alt\u003d\"V[i] \u003d V[i+1]\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~V[i] \u003d V[i+1]~\u003c/span\u003e\u003c/span\u003e.\u003c/li\u003e\n\u003cli\u003e(45 points) No additional constraints.\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003eFor each test case in which a valid journey exists, your solution:\u003c/p\u003e\n\u003cul\u003e\n\u003cli\u003egets full points if it returns a valid journey,\u003c/li\u003e\n\u003cli\u003egets \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/0bbdb311f08800272bae949158b49a35?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:4.261ex; height:2.343ex;\" alt\u003d\"35\\%\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~35\\%~\u003c/span\u003e\u003c/span\u003e of the points if it returns \u003ccode\u003etrue\u003c/code\u003e, an array of more than \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/aadef7fb3f44313bef8c7e299f932c7b?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:8.912ex; height:2.176ex;\" alt\u003d\"2\\,000\\,000\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~2\\,000\\,000~\u003c/span\u003e\u003c/span\u003e integers, or an array that does not describe a valid journey,\u003c/li\u003e\n\u003cli\u003egets \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/fc9653f00347ae032c0bb3370a2c7a76?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"0\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~0~\u003c/span\u003e\u003c/span\u003e points otherwise.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eFor each test case in which a valid journey does not exist, your solution:\u003c/p\u003e\n\u003cul\u003e\n\u003cli\u003egets full points if it returns \u003ccode\u003efalse\u003c/code\u003e,\u003c/li\u003e\n\u003cli\u003egets \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/fc9653f00347ae032c0bb3370a2c7a76?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"0\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~0~\u003c/span\u003e\u003c/span\u003e points otherwise.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eNote that the final score for each subtask is the minimum of the points for the test cases in the subtask.\u003c/p\u003e\n\u003ch4\u003eSample Grader\u003c/h4\u003e\n\u003cp\u003eThe sample grader reads the input in the following format:\u003c/p\u003e\n\u003cul\u003e\n\u003cli\u003eline \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/dc15aebf4fa2f4039e7e91a157d4b279?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"1\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~1~\u003c/span\u003e\u003c/span\u003e: \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/b9bed6e992be4c2b2ac2c71c2f82091b?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:5.086ex; height:2.176ex;\" alt\u003d\"N\\ M\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~N\\ M~\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\n\u003cli\u003eline \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/d8ce19d9e8cd64caf48f17b49a7058a3?v\u003d1715245171\" style\u003d\"vertical-align: -0.505ex; width:4.805ex; height:2.343ex;\" alt\u003d\"2+i\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~2+i~\u003c/span\u003e\u003c/span\u003e \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/7a805e85f4c7e2f0f1642ae233504801?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:16.416ex; height:2.843ex;\" alt\u003d\"(0 \\le i \\le M-1)\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~(0 \\le i \\le M-1)~\u003c/span\u003e\u003c/span\u003e: \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/def99b73e281d6f0a06b2d3d18217e77?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:8.343ex; height:2.843ex;\" alt\u003d\"U[i]\\ V[i]\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~U[i]\\ V[i]~\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eThe sample grader prints your answers in the following format:\u003c/p\u003e\n\u003cul\u003e\n\u003cli\u003eIf \u003ccode\u003efind_journey\u003c/code\u003e returns a \u003ccode\u003ebool\u003c/code\u003e:\u003cul\u003e\n\u003cli\u003eline \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/dc15aebf4fa2f4039e7e91a157d4b279?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"1\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~1~\u003c/span\u003e\u003c/span\u003e: \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/fc9653f00347ae032c0bb3370a2c7a76?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"0\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~0~\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\n\u003cli\u003eline \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/edff4a53ceab26bbeb9fa3434bd9765d?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"2\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~2~\u003c/span\u003e\u003c/span\u003e: \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/fc9653f00347ae032c0bb3370a2c7a76?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"0\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~0~\u003c/span\u003e\u003c/span\u003e if \u003ccode\u003efind_journey\u003c/code\u003e returns \u003ccode\u003efalse\u003c/code\u003e, or \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/dc15aebf4fa2f4039e7e91a157d4b279?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"1\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~1~\u003c/span\u003e\u003c/span\u003e otherwise.\u003c/li\u003e\n\u003c/ul\u003e\n\u003c/li\u003e\n\u003cli\u003eIf \u003ccode\u003efind_journey\u003c/code\u003e returns a \u003ccode\u003estd::vector\u0026lt;int\u0026gt;\u003c/code\u003e, denote the elements of this array by \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/65e3b8a6c626dba0568127d9cc92bd42?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:20.653ex; height:2.843ex;\" alt\u003d\"c[0], c[1], \\dots, c[k-1]\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~c[0], c[1], \\dots, c[k-1]~\u003c/span\u003e\u003c/span\u003e. The sample grader prints:\u003cul\u003e\n\u003cli\u003eline \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/dc15aebf4fa2f4039e7e91a157d4b279?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"1\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~1~\u003c/span\u003e\u003c/span\u003e: \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/dc15aebf4fa2f4039e7e91a157d4b279?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"1\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~1~\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\n\u003cli\u003eline \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/edff4a53ceab26bbeb9fa3434bd9765d?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"2\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~2~\u003c/span\u003e\u003c/span\u003e: \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/58614bc17dddddc4e51be1b63b3ce5ef?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.211ex; height:2.176ex;\" alt\u003d\"k\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~k~\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\n\u003cli\u003eline \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/86748ce269b76185f219ba13eeede716?v\u003d1715245171\" style\u003d\"vertical-align: -0.338ex; width:1.162ex; height:2.176ex;\" alt\u003d\"3\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~3~\u003c/span\u003e\u003c/span\u003e: \u003cspan class\u003d\"inline-math\"\u003e\u003cimg class\u003d\"tex-image\" src\u003d\"CDN_BASE_URL/aff36e141718744ac90af4f108e2c19f?v\u003d1715245171\" style\u003d\"vertical-align: -0.838ex; width:19.68ex; height:2.843ex;\" alt\u003d\"c[0]\\ c[1]\\ \\dots\\ c[k-1]\"\u003e\u003cspan class\u003d\"tex-text\" style\u003d\"display:none;\"\u003e~c[0]\\ c[1]\\ \\dots\\ c[k-1]~\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\n\u003c/ul\u003e\n\u003c/li\u003e\n\u003c/ul\u003e\n\u003ch4\u003eAttachment Package\u003c/h4\u003e\n\u003cp\u003eThe sample grader along with sample test cases are available \u003ca href\u003d\"https://dmoj.algome.me/data/ioi/22/ioi22p6/ioi22p6.zip\"\u003ehere\u003c/a\u003e.\u003c/p\u003e\n\u003c/div\u003e\n\u003chr\u003e\n\n\u003c/div\u003e"}}]}