Inputs: 13
Comment: END algorithm

0 12
1 7
2 6
3 4
5 8
9 11

0 1
2 3
4 6
5 9
7 12
8 11

0 2
1 4
3 7
6 12
10 11

4 9
6 10
7 8
11 12

1 7
3 4
5 6
8 9
10 11

0 5
1 3
2 6
4 7
8 10
9 11

2 5
6 8
9 10

1 2
3 5
4 6
7 8

2 3
4 5
6 7
8 9

3 4
5 6