{"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$$\u0027]]\n }\n });\n\u003c/script\u003e\n\u003cscript type\u003d\"text/javascript\" async src\u003d\"https://mathjax.codeforces.org/MathJax.js?config\u003dTeX-AMS_HTML-full\"\u003e\u003c/script\u003e","sections":[{"title":"","value":{"format":"HTML","content":"\u003cp\u003ePolycarp loves ciphers. He has invented his own cipher called Right-Left.\u003c/p\u003e\u003cp\u003eRight-Left cipher is used for strings. To encrypt the string $$$s\u003ds_{1}s_{2} \\dots s_{n}$$$ Polycarp uses the following algorithm:\u003c/p\u003e\u003cul\u003e \u003cli\u003e he writes down $$$s_1$$$, \u003c/li\u003e\u003cli\u003e he appends the current word with $$$s_2$$$ (i.e. writes down $$$s_2$$$ to the right of the current result), \u003c/li\u003e\u003cli\u003e he prepends the current word with $$$s_3$$$ (i.e. writes down $$$s_3$$$ to the left of the current result), \u003c/li\u003e\u003cli\u003e he appends the current word with $$$s_4$$$ (i.e. writes down $$$s_4$$$ to the right of the current result), \u003c/li\u003e\u003cli\u003e he prepends the current word with $$$s_5$$$ (i.e. writes down $$$s_5$$$ to the left of the current result), \u003c/li\u003e\u003cli\u003e and so on for each position until the end of $$$s$$$. \u003c/li\u003e\u003c/ul\u003e\u003cp\u003eFor example, if $$$s$$$\u003d\"\u003cspan class\u003d\"tex-font-style-tt\"\u003etechno\u003c/span\u003e\" the process is: \"\u003cspan class\u003d\"tex-font-style-tt\"\u003et\u003c/span\u003e\" $$$\\to$$$ \"\u003cspan class\u003d\"tex-font-style-tt\"\u003ete\u003c/span\u003e\" $$$\\to$$$ \"\u003cspan class\u003d\"tex-font-style-tt\"\u003ecte\u003c/span\u003e\" $$$\\to$$$ \"\u003cspan class\u003d\"tex-font-style-tt\"\u003ecteh\u003c/span\u003e\" $$$\\to$$$ \"\u003cspan class\u003d\"tex-font-style-tt\"\u003encteh\u003c/span\u003e\" $$$\\to$$$ \"\u003cspan class\u003d\"tex-font-style-tt\"\u003encteho\u003c/span\u003e\". So the encrypted $$$s$$$\u003d\"\u003cspan class\u003d\"tex-font-style-tt\"\u003etechno\u003c/span\u003e\" is \"\u003cspan class\u003d\"tex-font-style-tt\"\u003encteho\u003c/span\u003e\".\u003c/p\u003e\u003cp\u003eGiven string $$$t$$$ — the result of encryption of some string $$$s$$$. Your task is to decrypt it, i.e. find the string $$$s$$$.\u003c/p\u003e"}},{"title":"Input","value":{"format":"HTML","content":"\u003cp\u003eThe only line of the input contains $$$t$$$ — the result of encryption of some string $$$s$$$. It contains only lowercase Latin letters. The length of $$$t$$$ is between $$$1$$$ and $$$50$$$, inclusive.\u003c/p\u003e"}},{"title":"Output","value":{"format":"HTML","content":"\u003cp\u003ePrint such string $$$s$$$ that after encryption it equals $$$t$$$.\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\u003encteho\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003etechno\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\u003eerfdcoeocs\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003ecodeforces\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\u003ez\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003ez\n\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n"}}]}