Codeforces Round #540 (Div. 3) F1. Tree Cutting (Easy Version) 【DFS】
任意门:http://codeforces.com/contest/1118/problem/F1F1.TreeCutting(EasyVersion)timelimitpertest2secondsmemorylimitpertest256megabytesinputstandardinputoutputstandardoutputYouaregivenanundirectedtreeofnnv