5 5
1 2
3 1
2 4
3 4
4 5
1 2
3 2
3 1
4 1
3 5

YES
3
3 4 2 3
5 4 3 5
2 4 1 4

5 6
1 2
2 3
1 3
4 3
3 5
5 4
1 2
2 4
4 1
4 3
3 5
4 5

NO

提示

Sample 1 Explanation

Sample 2 Explanation