{"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\u003eA \u003cspan class\u003d\"tex-font-style-it\"\u003ebracket sequence\u003c/span\u003e is a string, containing only characters \"\u003cspan class\u003d\"tex-font-style-tt\"\u003e(\u003c/span\u003e\", \"\u003cspan class\u003d\"tex-font-style-tt\"\u003e)\u003c/span\u003e\", \"\u003cspan class\u003d\"tex-font-style-tt\"\u003e[\u003c/span\u003e\" and \"\u003cspan class\u003d\"tex-font-style-tt\"\u003e]\u003c/span\u003e\".\u003c/p\u003e\u003cp\u003eA \u003cspan class\u003d\"tex-font-style-it\"\u003ecorrect bracket sequence\u003c/span\u003e is a bracket sequence that can be transformed into a correct arithmetic expression by inserting characters \"\u003cspan class\u003d\"tex-font-style-tt\"\u003e1\u003c/span\u003e\" and \"\u003cspan class\u003d\"tex-font-style-tt\"\u003e+\u003c/span\u003e\" between the original characters of the sequence. For example, bracket sequences \"\u003cspan class\u003d\"tex-font-style-tt\"\u003e()[]\u003c/span\u003e\", \"\u003cspan class\u003d\"tex-font-style-tt\"\u003e([])\u003c/span\u003e\" are correct (the resulting expressions are: \"\u003cspan class\u003d\"tex-font-style-tt\"\u003e(1)+[1]\u003c/span\u003e\", \"\u003cspan class\u003d\"tex-font-style-tt\"\u003e([1+1]+1)\u003c/span\u003e\"), and \"\u003cspan class\u003d\"tex-font-style-tt\"\u003e](\u003c/span\u003e\" and \"\u003cspan class\u003d\"tex-font-style-tt\"\u003e[\u003c/span\u003e\" are not. \u003cspan class\u003d\"tex-font-style-bf\"\u003eThe empty string is a correct bracket sequence by definition.\u003c/span\u003e\u003c/p\u003e\u003cp\u003eA \u003cspan class\u003d\"tex-font-style-it\"\u003esubstring\u003c/span\u003e \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003es\u003c/i\u003e[\u003ci\u003el\u003c/i\u003e... \u003ci\u003er\u003c/i\u003e]\u003c/span\u003e \u003cspan class\u003d\"tex-span\"\u003e(1 ≤ \u003ci\u003el\u003c/i\u003e ≤ \u003ci\u003er\u003c/i\u003e ≤ |\u003ci\u003es\u003c/i\u003e|)\u003c/span\u003e of string \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003es\u003c/i\u003e \u003d \u003ci\u003es\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e1\u003c/sub\u003e\u003ci\u003es\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e2\u003c/sub\u003e... \u003ci\u003es\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e|\u003ci\u003es\u003c/i\u003e|\u003c/sub\u003e\u003c/span\u003e (where \u003cspan class\u003d\"tex-span\"\u003e|\u003ci\u003es\u003c/i\u003e|\u003c/span\u003e is the length of string \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003es\u003c/i\u003e\u003c/span\u003e) is the string \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003es\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e\u003ci\u003el\u003c/i\u003e\u003c/sub\u003e\u003ci\u003es\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e\u003ci\u003el\u003c/i\u003e + 1\u003c/sub\u003e... \u003ci\u003es\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e\u003ci\u003er\u003c/i\u003e\u003c/sub\u003e\u003c/span\u003e. \u003cspan class\u003d\"tex-font-style-bf\"\u003eThe empty string is a substring of any string by definition\u003c/span\u003e.\u003c/p\u003e\u003cp\u003eYou are given a bracket sequence, not necessarily correct. Find its substring which is a correct bracket sequence and contains as many opening square brackets «\u003cspan class\u003d\"tex-font-style-tt\"\u003e[\u003c/span\u003e» as possible.\u003c/p\u003e"}},{"title":"Input","value":{"format":"HTML","content":"\u003cp\u003eThe first and the only line contains the bracket sequence as a string, consisting only of characters \"\u003cspan class\u003d\"tex-font-style-tt\"\u003e(\u003c/span\u003e\", \"\u003cspan class\u003d\"tex-font-style-tt\"\u003e)\u003c/span\u003e\", \"\u003cspan class\u003d\"tex-font-style-tt\"\u003e[\u003c/span\u003e\" and \"\u003cspan class\u003d\"tex-font-style-tt\"\u003e]\u003c/span\u003e\". It is guaranteed that the string is non-empty and its length doesn\u0027t exceed \u003cspan class\u003d\"tex-span\"\u003e10\u003csup class\u003d\"upper-index\"\u003e5\u003c/sup\u003e\u003c/span\u003e characters.\u003c/p\u003e"}},{"title":"Output","value":{"format":"HTML","content":"\u003cp\u003eIn the first line print a single integer — the number of brackets «\u003cspan class\u003d\"tex-font-style-tt\"\u003e[\u003c/span\u003e» in the required bracket sequence. In the second line print the optimal sequence. If there are more than one optimal solutions print any of them.\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\u003e([])\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e1\n([])\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\u003e(((\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e0\n\n\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n"}}]}