SCUT_Pein

Description 　　After the regional contest, all the ACMers are walking alone a very long avenue to the dining hall in groups. Groups can vary in size for kinds of reasons, which means, several player

Andrew plays a game called "Civilization". Dima helps him. The game has n cities and m bidirectional roads. The cities are numbered from 1 to n. Between any pair of cities there either is a sin