{"trustable":false,"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\u003cscript\u003e window.katexOptions \u003d { disable: true }; \u003c/script\u003e\n\u003cscript type\u003d\"text/x-mathjax-config\"\u003e\n MathJax.Hub.Config({\n tex2jax: {\n inlineMath: [[\u0027$$$\u0027,\u0027$$$\u0027], [\u0027$\u0027,\u0027$\u0027]],\n displayMath: [[\u0027$$$$$$\u0027,\u0027$$$$$$\u0027], [\u0027$$\u0027,\u0027$$\u0027]]\n }\n });\n\u003c/script\u003e\n\u003cscript type\u003d\"text/javascript\" async src\u003d\"https://mathjax.codeforces.org/MathJax.js?config\u003dTeX-AMS_HTML-full\"\u003e\u003c/script\u003e","sections":[{"title":"","value":{"format":"MD","content":"给定 N 个数,如下构造一个倒三角的矩阵。\n\n首先第一行由这 N 个数构成。\n对于第二行,我们把第一行的相邻两项,**交替**相加、相减得到 N-1 个数。\n对于第三行,我们把第二行的相邻两项,继续交替相加、相减得到 N-2 个数。\n如此类推,直到我们得到第 N 行的唯一一个数。\n\n问最后一个数是多少。\n\n**交替相加、相减是指上一次运算取的那两项,如果是相加,则当前这次的运算是相减**(具体可以参考 sample 的图示)。"}},{"title":"Input","value":{"format":"MD","content":"\u003cp\u003eThe first line of input contains a single integer \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003en\u003c/i\u003e\u003c/span\u003e (\u003cspan class\u003d\"tex-span\"\u003e1 ≤ \u003ci\u003en\u003c/i\u003e ≤ 200000\u003c/span\u003e), the number of numbers written on the first row.\u003c/p\u003e\n\u003cp\u003eThe next line contains \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003en\u003c/i\u003e\u003c/span\u003e integers. Specifically, the \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ei\u003c/i\u003e\u003c/span\u003e-th one among these is \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\u003c/span\u003e (\u003cspan class\u003d\"tex-span\"\u003e1 ≤ \u003ci\u003ea\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e\u003ci\u003ei\u003c/i\u003e\u003c/sub\u003e ≤ 10\u003csup class\u003d\"upper-index\"\u003e9\u003c/sup\u003e\u003c/span\u003e), the \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ei\u003c/i\u003e\u003c/span\u003e-th number on the first row.\u003c/p\u003e"}},{"title":"Output","value":{"format":"MD","content":"\u003cp\u003eOutput a single integer on a line by itself, the number on the final row after performing the process above.\u003c/p\u003e\n\u003cp\u003eSince this number can be quite large, print only the non-negative remainder after dividing it by \u003cspan class\u003d\"tex-span\"\u003e10\u003csup class\u003d\"upper-index\"\u003e9\u003c/sup\u003e + 7\u003c/span\u003e.\u003c/p\u003e"}},{"title":"Sample 1","value":{"format":"MD","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\u003e5\n3 6 9 12 15\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e36\n\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n"}},{"title":"Sample 2","value":{"format":"MD","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\u003e4\n3 7 5 2\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e1000000006\n\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n"}},{"title":"Note","value":{"format":"MD","content":"\u003cp\u003eIn the first test case, the numbers written on the first row are \u003cspan class\u003d\"tex-span\"\u003e3\u003c/span\u003e, \u003cspan class\u003d\"tex-span\"\u003e6\u003c/span\u003e, \u003cspan class\u003d\"tex-span\"\u003e9\u003c/span\u003e, \u003cspan class\u003d\"tex-span\"\u003e12\u003c/span\u003e and \u003cspan class\u003d\"tex-span\"\u003e15\u003c/span\u003e.\u003c/p\u003e\n\u003cp\u003eKaren performs the operations as follows:\u003c/p\u003e\n\u003ccenter\u003e \n \u003cimg class\u003d\"tex-graphics\" src\u003d\"CDN_BASE_URL/2731f84da68a4217c6ecb632bcce03cc?v\u003d1645584932\" style\u003d\"max-width: 100.0%;max-height: 100.0%;\"\u003e \n\u003c/center\u003e\n\u003cp\u003eThe non-negative remainder after dividing the final number by \u003cspan class\u003d\"tex-span\"\u003e10\u003csup class\u003d\"upper-index\"\u003e9\u003c/sup\u003e + 7\u003c/span\u003e is still \u003cspan class\u003d\"tex-span\"\u003e36\u003c/span\u003e, so this is the correct output.\u003c/p\u003e\n\u003cp\u003eIn the second test case, the numbers written on the first row are \u003cspan class\u003d\"tex-span\"\u003e3\u003c/span\u003e, \u003cspan class\u003d\"tex-span\"\u003e7\u003c/span\u003e, \u003cspan class\u003d\"tex-span\"\u003e5\u003c/span\u003e and \u003cspan class\u003d\"tex-span\"\u003e2\u003c/span\u003e.\u003c/p\u003e\n\u003cp\u003eKaren performs the operations as follows:\u003c/p\u003e\n\u003ccenter\u003e \n \u003cimg class\u003d\"tex-graphics\" src\u003d\"CDN_BASE_URL/999daca4b98e2a0f3a1670ac11db3734?v\u003d1645584932\" style\u003d\"max-width: 100.0%;max-height: 100.0%;\"\u003e \n\u003c/center\u003e\n\u003cp\u003eThe non-negative remainder after dividing the final number by \u003cspan class\u003d\"tex-span\"\u003e10\u003csup class\u003d\"upper-index\"\u003e9\u003c/sup\u003e + 7\u003c/span\u003e is \u003cspan class\u003d\"tex-span\"\u003e10\u003csup class\u003d\"upper-index\"\u003e9\u003c/sup\u003e + 6\u003c/span\u003e, so this is the correct output.\u003c/p\u003e"}}]}