{"trustable":false,"prependHtml":"\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 async src\u003d\"https://mathjax.codeforces.org/MathJax.js?config\u003dTeX-AMS-MML_HTMLorMML\" type\u003d\"text/javascript\"\u003e\u003c/script\u003e","sections":[{"title":"题目描述","value":{"format":"HTML","content":"\u003cscript type\u003d\u0027text/x-mathjax-config\u0027\u003eMathJax.Hub.Config({tex2jax: { inlineMath: [[\u0027$\u0027,\u0027$\u0027]] } }); \u003c/script\u003e\n\u003cscript type\u003d\u0027text/javascript\u0027 src\u003d\u0027https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config\u003dTeX-AMS-MML_HTMLorMML\u0027\u003e\u003c/script\u003e\n\u003cscript type\u003d\u0027text/javascript\u0027\u003esetTimeout(function(){MathJax.Hub.Queue([\u0027Typeset\u0027, MathJax.Hub, \u0027left_view\u0027]);}, 2000);\u003c/script\u003e\n\u003cdiv class\u003d\"panel_content\"\u003e\nJCer很喜欢玩一种JC游戏,在一个机房里,有N位OIer,每个人都有一定的咕值,在每次JC中JCer允许机惨M个OIer并获得里面的咕值。但由于密码原因,有些OIer不能直接JC,要JC这些OIer必须先JC其他某一个特定的OIer。你能帮JCer算出要获得尽量多的咕值应该JC哪M个OIer吗?\n \u003cbr\u003e\n\u003c/div\u003e"}},{"title":"输入格式","value":{"format":"HTML","content":"每个测试实例首先包括2个整数,N,M.(1 \u0026lt;\u003d M \u0026lt;\u003d N \u0026lt;\u003d 200);在接下来的N行里,每行包括2个整数,a,b. 在第 i 行,a 代表要JC第 i 个OIer必须先JC第 a 个OIer,如果 a \u003d 0 则代表可以直接JC第 i 个OIer。b 代表第 i 个OIer的咕值数量, b \u0026gt;\u003d 0。当N \u003d 0, M \u003d 0输入结束。"}},{"title":"输出格式","value":{"format":"HTML","content":"对于每个测试实例,输出一个整数,代表JCer攻克M个OIer所获得的最多咕值的数量。"}},{"title":"样例输入","value":{"format":"HTML","content":"\u003cpre\u003e3 2\n0 1\n0 2\n0 3\n7 4\n2 2\n0 1\n0 4\n2 1\n7 1\n7 6\n2 2\n0 0\u003c/pre\u003e"}},{"title":"样例输出","value":{"format":"HTML","content":"\u003cpre\u003e5\n13\u003c/pre\u003e"}},{"title":"鸣谢","value":{"format":"HTML","content":"感谢CC提供的翻译。"}}]}