{"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\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":"HTML","content":"\u003cp\u003eMisha has an array of \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003en\u003c/i\u003e\u003c/span\u003e integers indexed by integers from \u003cspan class\u003d\"tex-span\"\u003e1\u003c/span\u003e to \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003en\u003c/i\u003e\u003c/span\u003e. Let\u0027s define \u003cspan class\u003d\"tex-font-style-it\"\u003epalindrome degree\u003c/span\u003e of array \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ea\u003c/i\u003e\u003c/span\u003e as the number of such index pairs \u003cspan class\u003d\"tex-span\"\u003e(\u003ci\u003el\u003c/i\u003e, \u003ci\u003er\u003c/i\u003e)(1 ≤ \u003ci\u003el\u003c/i\u003e ≤ \u003ci\u003er\u003c/i\u003e ≤ \u003ci\u003en\u003c/i\u003e)\u003c/span\u003e, that the elements from the \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003el\u003c/i\u003e\u003c/span\u003e-th to the \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003er\u003c/i\u003e\u003c/span\u003e-th one inclusive can be rearranged in such a way that the \u003cspan class\u003d\"tex-font-style-bf\"\u003ewhole\u003c/span\u003e array will be a palindrome. In other words, pair \u003cspan class\u003d\"tex-span\"\u003e(\u003ci\u003el\u003c/i\u003e, \u003ci\u003er\u003c/i\u003e)\u003c/span\u003e should meet the condition that after some rearranging of numbers on positions from \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003el\u003c/i\u003e\u003c/span\u003e to \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003er\u003c/i\u003e\u003c/span\u003e, inclusive (it is allowed not to rearrange the numbers at all), for any \u003cspan class\u003d\"tex-span\"\u003e1 ≤ \u003ci\u003ei\u003c/i\u003e ≤ \u003ci\u003en\u003c/i\u003e\u003c/span\u003e following condition holds: \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ea\u003c/i\u003e[\u003ci\u003ei\u003c/i\u003e] \u003d \u003ci\u003ea\u003c/i\u003e[\u003ci\u003en\u003c/i\u003e - \u003ci\u003ei\u003c/i\u003e + 1]\u003c/span\u003e. \u003c/p\u003e\u003cp\u003eYour task is to find the \u003cspan class\u003d\"tex-font-style-it\"\u003epalindrome degree\u003c/span\u003e of Misha\u0027s array.\u003c/p\u003e"}},{"title":"Input","value":{"format":"HTML","content":"\u003cp\u003eThe first line contains 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 ≤ 10\u003csup class\u003d\"upper-index\"\u003e5\u003c/sup\u003e\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eThe second line contains \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003en\u003c/i\u003e\u003c/span\u003e positive integers \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ea\u003c/i\u003e[\u003ci\u003ei\u003c/i\u003e]\u003c/span\u003e (\u003cspan class\u003d\"tex-span\"\u003e1 ≤ \u003ci\u003ea\u003c/i\u003e[\u003ci\u003ei\u003c/i\u003e] ≤ \u003ci\u003en\u003c/i\u003e\u003c/span\u003e), separated by spaces — the elements of Misha\u0027s array.\u003c/p\u003e"}},{"title":"Output","value":{"format":"HTML","content":"\u003cp\u003eIn a single line print the answer to the problem.\u003c/p\u003e"}},{"title":"Examples","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\u003e3\n2 2 2\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e6\n\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n"}},{"title":"","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\u003e6\n3 6 5 3 3 5\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e0\n\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n"}},{"title":"","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\u003e5\n5 5 2 5 2\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e4\n\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n"}},{"title":"Note","value":{"format":"HTML","content":"\u003cp\u003eIn the first sample test any possible pair \u003cspan class\u003d\"tex-span\"\u003e(\u003ci\u003el\u003c/i\u003e, \u003ci\u003er\u003c/i\u003e)\u003c/span\u003e meets the condition.\u003c/p\u003e\u003cp\u003eIn the third sample test following pairs \u003cspan class\u003d\"tex-span\"\u003e(1, 3), (1, 4), (1, 5), (2, 5)\u003c/span\u003e meet the condition.\u003c/p\u003e"}}]}