{"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\u003eAlice cansou de jogar o jogo da marcação pelas regras usuais, então ela ofereceu a Bob uma pequena modificação. Agora o jogo deve ser jogado em uma árvore enraizada não direcionada de \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003en\u003c/i\u003e\u003c/span\u003e vértices. O vértice \u003cspan class\u003d\"tex-font-style-tt\"\u003e1\u003c/span\u003e é a raiz da árvore.\u003c/p\u003e\u003cp\u003eAlice começa no vértice \u003cspan class\u003d\"tex-font-style-tt\"\u003e1\u003c/span\u003e e Bob começa no vértice \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ex\u003c/i\u003e\u003c/span\u003e (\u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ex\u003c/i\u003e ≠ 1\u003c/span\u003e). Os movimentos são feitos em turnos, Bob começa. Em um movimento, pode-se ficar no vértice atual ou viajar para o vizinho.\u003c/p\u003e\u003cp\u003eO jogo termina quando Alice vai para o mesmo vértice onde Bob está. Alice quer minimizar o número total de movimentos e Bob quer maximizá-lo.\u003c/p\u003e\u003cp\u003eVocê deve escrever um programa que determinará quantos movimentos o jogo durará.\u003c/p\u003e"}},{"title":"Entrada","value":{"format":"HTML","content":"\u003cp\u003eA primeira linha contém dois números inteiros \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003en\u003c/i\u003e\u003c/span\u003e e \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ex\u003c/i\u003e\u003c/span\u003e (\u003cspan class\u003d\"tex-span\"\u003e2 ≤ \u003ci\u003en\u003c/i\u003e ≤ 2·10\u003csup class\u003d\"upper-index\"\u003e5\u003c/sup\u003e\u003c/span\u003e, \u003cspan class\u003d\"tex-span\"\u003e2 ≤ \u003ci\u003ex\u003c/i\u003e ≤ \u003ci\u003en\u003c/i\u003e\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eCada uma das próximas \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003en\u003c/i\u003e - 1\u003c/span\u003e linhas contém dois números inteiros \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 (\u003cspan class\u003d\"tex-span\"\u003e1 ≤ \u003ci\u003ea\u003c/i\u003e, \u003ci\u003eb\u003c/i\u003e ≤ \u003ci\u003en\u003c/i\u003e\u003c/span\u003e) — arestas da árvore. É garantido que as arestas formam uma árvore válida.\u003c/p\u003e"}},{"title":"Saída","value":{"format":"HTML","content":"\u003cp\u003eImprima o número total de movimentos que Alice e Bob farão.\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\u003e4 3\n1 2\n2 3\n2 4\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e4\n\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e"}},{"title":"Exemplo 2","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 2\n1 2\n2 3\n3 4\n2 5\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e6\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, a árvore parece com isso:\u003c/p\u003e\u003ccenter\u003e \u003cimg class\u003d\"tex-graphics\" src\u003d\"CDN_BASE_URL/62ed8561a039ddede670ce86674e6c54?v\u003d1701926720\" style\u003d\"max-width: 100.0%;max-height: 100.0%;\"\u003e \u003c/center\u003e\u003cp\u003eO vértice vermelho é a posição inicial de Alice, o azul é a de Bob. Bob fará o jogo durar mais tempo ficando no vértice \u003cspan class\u003d\"tex-font-style-tt\"\u003e3\u003c/span\u003e durante todo o jogo. Então aqui estão os movimentos:\u003c/p\u003e\u003cp\u003e\u003cspan class\u003d\"tex-font-style-bf\"\u003eB\u003c/span\u003e: ficar no vértice \u003cspan class\u003d\"tex-font-style-tt\"\u003e3\u003c/span\u003e\u003c/p\u003e\u003cp\u003e\u003cspan class\u003d\"tex-font-style-bf\"\u003eA\u003c/span\u003e: ir para o vértice \u003cspan class\u003d\"tex-font-style-tt\"\u003e2\u003c/span\u003e\u003c/p\u003e\u003cp\u003e\u003cspan class\u003d\"tex-font-style-bf\"\u003eB\u003c/span\u003e: ficar no vértice \u003cspan class\u003d\"tex-font-style-tt\"\u003e3\u003c/span\u003e\u003c/p\u003e\u003cp\u003e\u003cspan class\u003d\"tex-font-style-bf\"\u003eA\u003c/span\u003e: ir para o vértice \u003cspan class\u003d\"tex-font-style-tt\"\u003e3\u003c/span\u003e\u003c/p\u003e\u003cp\u003eNo segundo exemplo, a árvore parece com isso:\u003c/p\u003e\u003ccenter\u003e \u003cimg class\u003d\"tex-graphics\" src\u003d\"CDN_BASE_URL/6710684550e6a9867defe3ad61795a67?v\u003d1701926720\" style\u003d\"max-width: 100.0%;max-height: 100.0%;\"\u003e \u003c/center\u003e\u003cp\u003eOs movimentos na estratégia ótima são:\u003c/p\u003e\u003cp\u003e\u003cspan class\u003d\"tex-font-style-bf\"\u003eB\u003c/span\u003e: ir para o vértice \u003cspan class\u003d\"tex-font-style-tt\"\u003e3\u003c/span\u003e\u003c/p\u003e\u003cp\u003e\u003cspan class\u003d\"tex-font-style-bf\"\u003eA\u003c/span\u003e: ir para o vértice \u003cspan class\u003d\"tex-font-style-tt\"\u003e2\u003c/span\u003e\u003c/p\u003e\u003cp\u003e\u003cspan class\u003d\"tex-font-style-bf\"\u003eB\u003c/span\u003e: ir para o vértice \u003cspan class\u003d\"tex-font-style-tt\"\u003e4\u003c/span\u003e\u003c/p\u003e\u003cp\u003e\u003cspan class\u003d\"tex-font-style-bf\"\u003eA\u003c/span\u003e: ir para o vértice \u003cspan class\u003d\"tex-font-style-tt\"\u003e3\u003c/span\u003e\u003c/p\u003e\u003cp\u003e\u003cspan class\u003d\"tex-font-style-bf\"\u003eB\u003c/span\u003e: ficar no vértice \u003cspan class\u003d\"tex-font-style-tt\"\u003e4\u003c/span\u003e\u003c/p\u003e\u003cp\u003e\u003cspan class\u003d\"tex-font-style-bf\"\u003eA\u003c/span\u003e: ir para o vértice \u003cspan class\u003d\"tex-font-style-tt\"\u003e4\u003c/span\u003e\u003c/p\u003e"}}]}