{"trustable":true,"prependHtml":"\u003cstyle type\u003d\"text/css\"\u003e\n #problem-body \u003e pre {\n display: block;\n padding: 9.5px;\n margin: 0 0 10px;\n font-size: 13px;\n line-height: 1.42857143;\n word-break: break-all;\n word-wrap: break-word;\n color: #333;\n background: rgba(255, 255, 255, 0.5);\n border: 1px solid #ccc;\n border-radius: 6px;\n }\n\u003c/style\u003e\n","sections":[{"title":"","value":{"format":"HTML","content":"\u003cdiv id\u003d\"problem-body\"\u003e\n\t\r\n\u003ctable class\u003d\"problems\" width\u003d\"100%\"\u003e\u003ctbody\u003e\u003ctr class\u003d\"navigation\"\u003e\r\n\u003ctd width\u003d\"50%\"\u003e\u003ca href\u003d\"https://www.spoj.com/problems/M3TILE/en/\"\u003eEnglish\u003c/a\u003e\u003c/td\u003e \r\n\u003ctd width\u003d\"50%\"\u003e\u003ca href\u003d\"https://www.spoj.com/problems/M3TILE/vn/\"\u003eVietnamese\u003c/a\u003e\u003c/td\u003e \r\n\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\r\n\r\n\r\n\u003cp\u003eIn how many ways can you tile a 3×n rectangle with 2×1 dominoes?\u003c/p\u003e\r\n\r\n\u003cp\u003eHere is a sample tiling of a 3×12 rectangle.\u003c/p\u003e\r\n\u003cp\u003e\u003c/p\u003e\u003ccenter\u003e\u003cimg src\u003d\"CDN_BASE_URL/886fec46d8d895ec81c1ae00f44dac73?v\u003d1715196912\"\u003e\u003c/center\u003e\u003cp\u003e\u003c/p\u003e\r\n\u003cp\u003eInput consists of several test cases followed by a line containing -1.\r\nEach test case is a line containing an integer 0 ≤ n ≤ 30. For each test\r\ncase, output one integer number giving the number of possible tilings.\u003c/p\u003e\r\n\r\n\u003ch3\u003eExample\u003c/h3\u003e\r\n\u003cdiv\u003e\u003ctable class\u003d\"vjudge_sample\"\u003e\n\u003cthead\u003e\n \u003ctr\u003e\n \u003cth\u003eInput\u003c/th\u003e\n \u003cth\u003eOutput\u003c/th\u003e\n \u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\u003cpre\u003e2\r\n8\r\n12\r\n-1\r\n\r\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e3\r\n153\r\n2131\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003c/div\u003e\r\n\r\n\r\n \r\n\u003c/div\u003e"}}]}