{"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\u003eThere are \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003en\u003c/i\u003e\u003c/span\u003e cities and \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003em\u003c/i\u003e\u003c/span\u003e two-way roads in Berland, each road connects two cities. It is known that there is no more than one road connecting each pair of cities, and there is no road which connects the city with itself. It is possible that there is no way to get from one city to some other city using only these roads.\u003c/p\u003e\u003cp\u003eThe road minister decided to make a reform in Berland and to orient all roads in the country, i.e. to make each road one-way. The minister wants to \u003cspan class\u003d\"tex-font-style-bf\"\u003emaximize\u003c/span\u003e the number of cities, for which the number of roads that begins in the city \u003cspan class\u003d\"tex-font-style-bf\"\u003eequals\u003c/span\u003e to the number of roads that ends in it.\u003c/p\u003e"}},{"title":"Input","value":{"format":"HTML","content":"\u003cp\u003eThe first line contains a positive integer \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003et\u003c/i\u003e\u003c/span\u003e (\u003cspan class\u003d\"tex-span\"\u003e1 ≤ \u003ci\u003et\u003c/i\u003e ≤ 200\u003c/span\u003e)\u0026nbsp;— the number of testsets in the input.\u003c/p\u003e\u003cp\u003eEach of the testsets is given in the following way. The first line contains two integers \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003en\u003c/i\u003e\u003c/span\u003e and \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003em\u003c/i\u003e\u003c/span\u003e (\u003cspan class\u003d\"tex-span\"\u003e1 ≤ \u003ci\u003en\u003c/i\u003e ≤ 200\u003c/span\u003e, \u003cspan class\u003d\"tex-span\"\u003e0 ≤ \u003ci\u003em\u003c/i\u003e ≤ \u003ci\u003en\u003c/i\u003e·(\u003ci\u003en\u003c/i\u003e - 1) / 2\u003c/span\u003e)\u0026nbsp;— the number of cities and the number of roads in Berland. \u003c/p\u003e\u003cp\u003eThe next \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003em\u003c/i\u003e\u003c/span\u003e lines contain the description of roads in Berland. Each line contains two integers \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003eu\u003c/i\u003e\u003c/span\u003e and \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ev\u003c/i\u003e\u003c/span\u003e (\u003cspan class\u003d\"tex-span\"\u003e1 ≤ \u003ci\u003eu\u003c/i\u003e, \u003ci\u003ev\u003c/i\u003e ≤ \u003ci\u003en\u003c/i\u003e\u003c/span\u003e)\u0026nbsp;— the cities the corresponding road connects. It\u0027s guaranteed that there are no self-loops and multiple roads. It is possible that there is no way along roads between a pair of cities.\u003c/p\u003e\u003cp\u003eIt is guaranteed that the total number of cities in all testset of input data doesn\u0027t exceed \u003cspan class\u003d\"tex-span\"\u003e200\u003c/span\u003e.\u003c/p\u003e\u003cp\u003ePay attention that for \u003cspan class\u003d\"tex-font-style-bf\"\u003ehacks\u003c/span\u003e, you can only use tests consisting of \u003cspan class\u003d\"tex-font-style-bf\"\u003eone testset\u003c/span\u003e, so \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003et\u003c/i\u003e\u003c/span\u003e should be equal to one.\u003c/p\u003e"}},{"title":"Output","value":{"format":"HTML","content":"\u003cp\u003eFor each testset print the maximum number of such cities that the number of roads that begins in the city, is equal to the number of roads that ends in it.\u003c/p\u003e\u003cp\u003eIn the next \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003em\u003c/i\u003e\u003c/span\u003e lines print oriented roads. First print the number of the city where the road begins and then the number of the city where the road ends. If there are several answers, print any of them. It is allowed to print roads in each test in arbitrary order. Each road should be printed exactly once. \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\u003e2\n5 5\n2 1\n4 5\n2 3\n1 3\n3 5\n7 2\n3 7\n4 2\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e3\n1 3\n3 5\n5 4\n3 2\n2 1\n3\n2 4\n3 7\n\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n"}}]}