{"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$$\u0027]]\n }\n });\n\u003c/script\u003e\n\u003cscript type\u003d\"text/javascript\" async src\u003d\"https://mathjax.codeforces.org/MathJax.js?config\u003dTeX-AMS_HTML-full\"\u003e\u003c/script\u003e","sections":[{"title":"","value":{"format":"HTML","content":"\u003cp\u003eYou are given a string $$$s\u003ds_1s_2\\dots s_n$$$ of length $$$n$$$, which only contains digits $$$1$$$, $$$2$$$, ..., $$$9$$$.\u003c/p\u003e\u003cp\u003eA substring $$$s[l \\dots r]$$$ of $$$s$$$ is a string $$$s_l s_{l + 1} s_{l + 2} \\ldots s_r$$$. A substring $$$s[l \\dots r]$$$ of $$$s$$$ is called \u003cspan class\u003d\"tex-font-style-it\"\u003eeven\u003c/span\u003e if the number represented by it is even. \u003c/p\u003e\u003cp\u003eFind the number of even substrings of $$$s$$$. Note, that even if some substrings are equal as strings, but have different $$$l$$$ and $$$r$$$, they are counted as \u003cspan class\u003d\"tex-font-style-bf\"\u003edifferent\u003c/span\u003e substrings.\u003c/p\u003e"}},{"title":"Input","value":{"format":"HTML","content":"\u003cp\u003eThe first line contains an integer $$$n$$$ ($$$1 \\le n \\le 65000$$$)\u0026nbsp;— the length of the string $$$s$$$.\u003c/p\u003e\u003cp\u003eThe second line contains a string $$$s$$$ of length $$$n$$$. The string $$$s$$$ consists only of digits $$$1$$$, $$$2$$$, ..., $$$9$$$.\u003c/p\u003e"}},{"title":"Output","value":{"format":"HTML","content":"\u003cp\u003ePrint the number of even substrings of $$$s$$$.\u003c/p\u003e"}},{"title":"Examples","value":{"format":"HTML","content":"\u003ctable class\u003d\u0027vjudge_sample\u0027\u003e\n\u003cthead\u003e\n \u003ctr\u003e\n \u003cth\u003eInput\u003c/th\u003e\n \u003cth\u003eOutput\u003c/th\u003e\n \u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\u003cpre\u003e4\n1234\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e6\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n"}},{"title":"","value":{"format":"HTML","content":"\u003ctable class\u003d\u0027vjudge_sample\u0027\u003e\n\u003cthead\u003e\n \u003ctr\u003e\n \u003cth\u003eInput\u003c/th\u003e\n \u003cth\u003eOutput\u003c/th\u003e\n \u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\u003cpre\u003e4\n2244\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e10\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n"}},{"title":"Note","value":{"format":"HTML","content":"\u003cp\u003eIn the first example, the $$$[l, r]$$$ pairs corresponding to even substrings are: \u003c/p\u003e\u003cul\u003e \u003cli\u003e $$$s[1 \\dots 2]$$$\u003c/li\u003e\u003cli\u003e $$$s[2 \\dots 2]$$$\u003c/li\u003e\u003cli\u003e $$$s[1 \\dots 4]$$$\u003c/li\u003e\u003cli\u003e $$$s[2 \\dots 4]$$$\u003c/li\u003e\u003cli\u003e $$$s[3 \\dots 4]$$$\u003c/li\u003e\u003cli\u003e $$$s[4 \\dots 4]$$$ \u003c/li\u003e\u003c/ul\u003e\u003cp\u003eIn the second example, all $$$10$$$ substrings of $$$s$$$ are even substrings. Note, that while substrings $$$s[1 \\dots 1]$$$ and $$$s[2 \\dots 2]$$$ both define the substring \"\u003cspan class\u003d\"tex-font-style-tt\"\u003e2\u003c/span\u003e\", they are still counted as different substrings.\u003c/p\u003e"}}]}