{"raw_statement":[{"iden":"statement","content":"See the problem statement here: [http://codeforces.com/contest/921/problem/01](//codeforces.com/contest/921/problem/01)."}],"translated_statement":[{"iden":"statement","content":"请在此查看题目描述：http://codeforces.com/contest/921/problem/01.\n\n"}],"sample_group":[],"show_order":[],"formal_statement":"**Definitions**  \nLet $ n \\in \\mathbb{Z} $ be the number of vertices in a tree.  \nLet $ T = (V, E) $ be a tree with $ V = \\{1, 2, \\dots, n\\} $ and $ |E| = n - 1 $.  \nLet $ d(v) $ denote the degree of vertex $ v \\in V $.  \n\n**Constraints**  \n1. $ 1 \\le n \\le 2 \\cdot 10^5 $  \n2. The graph $ T $ is a tree (connected, acyclic, undirected).  \n\n**Objective**  \nFind the maximum number of vertices that can be colored such that no two adjacent vertices are both colored, i.e., find the size of the maximum independent set in $ T $.","simple_statement":null,"has_page_source":false}