{"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\u003eUma empresa tem \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003en\u003c/i\u003e\u003c/span\u003e funcionários numerados de \u003cspan class\u003d\"tex-span\"\u003e1\u003c/span\u003e a \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003en\u003c/i\u003e\u003c/span\u003e. Cada funcionário não tem um gerente imediato ou tem exatamente um gerente imediato, que é outro funcionário com um número diferente. Um funcionário \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003eA\u003c/i\u003e\u003c/span\u003e é considerado o \u003cspan class\u003d\"tex-font-style-underline\"\u003esuperior\u003c/span\u003e de outro funcionário \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003eB\u003c/i\u003e\u003c/span\u003e se pelo menos uma das seguintes condições for verdadeira:\u003c/p\u003e\u003cul\u003e \u003cli\u003e O funcionário \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003eA\u003c/i\u003e\u003c/span\u003e é o gerente imediato do funcionário \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003eB\u003c/i\u003e\u003c/span\u003e \u003c/li\u003e\u003cli\u003e O funcionário \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003eB\u003c/i\u003e\u003c/span\u003e tem um gerente imediato funcionário \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003eC\u003c/i\u003e\u003c/span\u003e tal que o funcionário \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003eA\u003c/i\u003e\u003c/span\u003e é o superior do funcionário \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003eC\u003c/i\u003e\u003c/span\u003e. \u003c/li\u003e\u003c/ul\u003e\u003cp\u003eA empresa não terá um ciclo de gerenciamento. Ou seja, não existirá um funcionário que é o superior de seu próprio gerente imediato.\u003c/p\u003e\u003cp\u003eHoje a empresa vai organizar uma festa. Isso envolve dividir todos os \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003en\u003c/i\u003e\u003c/span\u003e funcionários em vários grupos: cada funcionário deve pertencer a exatamente um grupo. Além disso, dentro de um único grupo, não deve haver dois funcionários \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003eA\u003c/i\u003e\u003c/span\u003e e \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003eB\u003c/i\u003e\u003c/span\u003e tal que \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003eA\u003c/i\u003e\u003c/span\u003e seja o superior de \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003eB\u003c/i\u003e\u003c/span\u003e.\u003c/p\u003e\u003cp\u003eQual é o número mínimo de grupos que devem ser formados?\u003c/p\u003e"}},{"title":"Entrada","value":{"format":"HTML","content":"\u003cp\u003eA primeira linha contém o inteiro \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003en\u003c/i\u003e\u003c/span\u003e (\u003cspan class\u003d\"tex-span\"\u003e1 ≤ \u003ci\u003en\u003c/i\u003e ≤ 2000\u003c/span\u003e) - o número de funcionários.\u003c/p\u003e\u003cp\u003eAs próximas \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003en\u003c/i\u003e\u003c/span\u003e linhas contêm os inteiros \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ep\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e\u003ci\u003ei\u003c/i\u003e\u003c/sub\u003e\u003c/span\u003e (\u003cspan class\u003d\"tex-span\"\u003e1 ≤ \u003ci\u003ep\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e\u003ci\u003ei\u003c/i\u003e\u003c/sub\u003e ≤ \u003ci\u003en\u003c/i\u003e\u003c/span\u003e ou \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ep\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e\u003ci\u003ei\u003c/i\u003e\u003c/sub\u003e \u003d \u003c/span\u003e-1). Cada \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ep\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e\u003ci\u003ei\u003c/i\u003e\u003c/sub\u003e\u003c/span\u003e denota o gerente imediato para o \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ei\u003c/i\u003e\u003c/span\u003e-ésimo funcionário. Se \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ep\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e\u003ci\u003ei\u003c/i\u003e\u003c/sub\u003e\u003c/span\u003e for -1, isso significa que o \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ei\u003c/i\u003e\u003c/span\u003e-ésimo funcionário não tem um gerente imediato. \u003c/p\u003e\u003cp\u003eÉ garantido que nenhum funcionário será o gerente imediato de si mesmo (\u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ep\u003c/i\u003e\u003csub class\u003d\"lower-index\"\u003e\u003ci\u003ei\u003c/i\u003e\u003c/sub\u003e ≠ \u003ci\u003ei\u003c/i\u003e\u003c/span\u003e). Além disso, não haverá ciclos de gerenciamento.\u003c/p\u003e"}},{"title":"Saída","value":{"format":"HTML","content":"\u003cp\u003eImprima um único inteiro que denote o número mínimo de grupos que serão formados na festa.\u003c/p\u003e"}},{"title":"Exemplo 1","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\u003e5\n-1\n1\n2\n1\n-1\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e3\n\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e"}},{"title":"Nota","value":{"format":"HTML","content":"\u003cp\u003eNo primeiro exemplo, três grupos são suficientes, por exemplo: \u003c/p\u003e\u003cul\u003e \u003cli\u003e Funcionário 1 \u003c/li\u003e\u003cli\u003e Funcionários 2 e 4 \u003c/li\u003e\u003cli\u003e Funcionários 3 e 5 \u003c/li\u003e\u003c/ul\u003e"}}]}