{"trustable":true,"prependHtml":"\u003cstyle type\u003d\u0027text/css\u0027\u003e\n .input, .output {\n border: 1px solid #888888;\n }\n .output {\n margin-bottom: 1em;\n position: relative;\n top: -1px;\n }\n .output pre, .input pre {\n background-color: #EFEFEF;\n line-height: 1.25em;\n margin: 0;\n padding: 0.25em;\n }\n \u003c/style\u003e\n \u003clink rel\u003d\"stylesheet\" href\u003d\"//codeforces.org/s/96598/css/problem-statement.css\" type\u003d\"text/css\" /\u003e\n\u003cscript\u003e\n window.katexOptions \u003d {\n delimiters: [\n {left: \u0027$$$$$$\u0027, right: \u0027$$$$$$\u0027, display: true},\n {left: \u0027$$$\u0027, right: \u0027$$$\u0027, display: false},\n {left: \u0027$$\u0027, right: \u0027$$\u0027, display: true},\n {left: \u0027$\u0027, right: \u0027$\u0027, display: false}\n ]\n };\n\u003c/script\u003e\n","sections":[{"title":"","value":{"format":"HTML","content":"\u003cp\u003eLittle X và Little Z là bạn tốt. Họ luôn trò chuyện trực tuyến. Nhưng cả hai đều có lịch trình.\u003c/p\u003e\u003cp\u003eLittle Z có lịch trình cố định. Anh ấy luôn trực tuyến vào bất kỳ thời điểm nào giữa \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ea\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e1\u003c/sub\u003e\u003c/span\u003e và \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003eb\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e1\u003c/sub\u003e\u003c/span\u003e, giữa \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ea\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e2\u003c/sub\u003e\u003c/span\u003e và \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003eb\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e2\u003c/sub\u003e\u003c/span\u003e, ..., giữa \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ea\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e\u003ci\u003ep\u003c/i\u003e\u003c/sub\u003e\u003c/span\u003e và \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003eb\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e\u003ci\u003ep\u003c/i\u003e\u003c/sub\u003e\u003c/span\u003e (tất cả đều bao gồm cả hai đầu). Nhưng lịch trình của Little X khá kỳ lạ, nó phụ thuộc vào thời gian anh ấy thức dậy. Nếu anh ấy thức dậy vào thời gian \u003cspan class\u003d\"tex-span\"\u003e0\u003c/span\u003e, anh ấy sẽ trực tuyến vào bất kỳ thời điểm nào giữa \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ec\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e1\u003c/sub\u003e\u003c/span\u003e và \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ed\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e1\u003c/sub\u003e\u003c/span\u003e, giữa \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ec\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e2\u003c/sub\u003e\u003c/span\u003e và \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ed\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e2\u003c/sub\u003e\u003c/span\u003e, ..., giữa \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ec\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e\u003ci\u003eq\u003c/i\u003e\u003c/sub\u003e\u003c/span\u003e và \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ed\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e\u003ci\u003eq\u003c/i\u003e\u003c/sub\u003e\u003c/span\u003e (tất cả đều bao gồm cả hai đầu). Nhưng nếu anh ấy thức dậy vào thời gian \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003et\u003c/i\u003e\u003c/span\u003e, những đoạn này sẽ bị dịch chuyển bởi \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003et\u003c/i\u003e\u003c/span\u003e. Chúng trở thành \u003cspan class\u003d\"tex-span\"\u003e[\u003ci\u003ec\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e\u003ci\u003ei\u003c/i\u003e\u003c/sub\u003e + \u003ci\u003et\u003c/i\u003e, \u003ci\u003ed\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e\u003ci\u003ei\u003c/i\u003e\u003c/sub\u003e + \u003ci\u003et\u003c/i\u003e]\u003c/span\u003e (cho tất cả \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ei\u003c/i\u003e\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eNếu vào một thời điểm nào đó, cả Little X và Little Z đều trực tuyến cùng một lúc, họ có thể trò chuyện trực tuyến một cách vui vẻ. Bạn biết rằng Little X có thể thức dậy vào một thời điểm nguyên giữa \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003el\u003c/i\u003e\u003c/span\u003e và \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003er\u003c/i\u003e\u003c/span\u003e (cả hai đầu đều bao gồm). Bạn cũng biết rằng Little X muốn thức dậy vào thời điểm phù hợp để trò chuyện với Little Z (họ phải có ít nhất một thời điểm chung trong lịch trình). Có bao nhiêu thời điểm nguyên từ đoạn \u003cspan class\u003d\"tex-span\"\u003e[\u003ci\u003el\u003c/i\u003e, \u003ci\u003er\u003c/i\u003e]\u003c/span\u003e phù hợp với điều đó?\u003c/p\u003e"}},{"title":"Nhập","value":{"format":"HTML","content":"\u003cp\u003eDòng đầu tiên chứa bốn số nguyên cách nhau bởi dấu cách \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ep\u003c/i\u003e, \u003ci\u003eq\u003c/i\u003e, \u003ci\u003el\u003c/i\u003e, \u003ci\u003er\u003c/i\u003e\u003c/span\u003e (\u003cspan class\u003d\"tex-span\"\u003e1 ≤ \u003ci\u003ep\u003c/i\u003e, \u003ci\u003eq\u003c/i\u003e ≤ 50;\u0026nbsp;0 ≤ \u003ci\u003el\u003c/i\u003e ≤ \u003ci\u003er\u003c/i\u003e ≤ 1000\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eMỗi dòng tiếp theo \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ep\u003c/i\u003e\u003c/span\u003e dòng chứa hai số nguyên cách nhau bởi dấu cách \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ea\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e\u003ci\u003ei\u003c/i\u003e\u003c/sub\u003e, \u003ci\u003eb\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e\u003ci\u003ei\u003c/i\u003e\u003c/sub\u003e\u003c/span\u003e (\u003cspan class\u003d\"tex-span\"\u003e0 ≤ \u003ci\u003ea\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e\u003ci\u003ei\u003c/i\u003e\u003c/sub\u003e \u0026lt; \u003ci\u003eb\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e\u003ci\u003ei\u003c/i\u003e\u003c/sub\u003e ≤ 1000\u003c/span\u003e). Mỗi dòng tiếp theo \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003eq\u003c/i\u003e\u003c/span\u003e dòng chứa hai số nguyên cách nhau bởi dấu cách \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ec\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e\u003ci\u003ej\u003c/i\u003e\u003c/sub\u003e, \u003ci\u003ed\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e\u003ci\u003ej\u003c/i\u003e\u003c/sub\u003e\u003c/span\u003e (\u003cspan class\u003d\"tex-span\"\u003e0 ≤ \u003ci\u003ec\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e\u003ci\u003ej\u003c/i\u003e\u003c/sub\u003e \u0026lt; \u003ci\u003ed\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e\u003ci\u003ej\u003c/i\u003e\u003c/sub\u003e ≤ 1000\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eĐảm bảo rằng \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003eb\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e\u003ci\u003ei\u003c/i\u003e\u003c/sub\u003e \u0026lt; \u003ci\u003ea\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e\u003ci\u003ei\u003c/i\u003e + 1\u003c/sub\u003e\u003c/span\u003e và \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ed\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e\u003ci\u003ej\u003c/i\u003e\u003c/sub\u003e \u0026lt; \u003ci\u003ec\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e\u003ci\u003ej\u003c/i\u003e + 1\u003c/sub\u003e\u003c/span\u003e đối với tất cả các \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ei\u003c/i\u003e\u003c/span\u003e và \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ej\u003c/i\u003e\u003c/span\u003e.\u003c/p\u003e"}},{"title":"Đầu ra","value":{"format":"HTML","content":"\u003cp\u003eĐầu ra một số nguyên duy nhất — số lượng thời điểm từ đoạn \u003cspan class\u003d\"tex-span\"\u003e[\u003ci\u003el\u003c/i\u003e, \u003ci\u003er\u003c/i\u003e]\u003c/span\u003e phù hợp cho cuộc trò chuyện trực tuyến.\u003c/p\u003e"}},{"title":"Ví dụ 1","value":{"format":"HTML","content":"\u003ctable class\u003d\u0027vjudge_sample\u0027\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\u003e1 1 0 4\n2 3\n0 1\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e3\n\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e"}},{"title":"Ví dụ 2","value":{"format":"HTML","content":"\u003ctable class\u003d\u0027vjudge_sample\u0027\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 3 0 20\n15 17\n23 26\n1 4\n7 11\n15 17\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e20\n\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e"}}]}