P3523-[POI2011]DYN-Dynamite
P3523-[POI2011]DYN-Dynamite 题目: 题目描述: The Byteotian Cave is composed of $n$ chambers and $n-1$ corridors that connect them. For every pair of chambers there is unique way to move from one of them to another without leaving the cave. Dynamite charges are set up in certain chambers. A fuse is laid along every corridor. In every chamber the fuses from the adjacent corridors meet at