#P1781. B-Commemorative Race
B-Commemorative Race
题目描述
输入格式
输出格式
样例
4 4
1 2
1 3
3 4
2 4
2
7 6
1 2
2 3
2 5
6 3
7 2
3 4
2
7 5
1 2
2 3
3 4
5 6
6 7
0
提示
By QLU—王梦涛
4 4
1 2
1 3
3 4
2 4
2
7 6
1 2
2 3
2 5
6 3
7 2
3 4
2
7 5
1 2
2 3
3 4
5 6
6 7
0
By QLU—王梦涛