20 23
7 3 0 1
3 2 1 0
5 6 1 1
6 4 1 0
4 1 0 1
2 5 0 1
7 4 0 0
1 7 0 1
7 6 1 1
3 5 1 0
3 6 0 1
17 8 0 0
8 16 1 1
19 18 0 0
18 1 1 1
18 20 1 1
20 19 1 1
9 10 1 1
10 13 0 0
13 14 0 1
14 9 0 1
9 15 0 0
9 13 0 1