8
0 12 9 18 16 1 12 4
15 0 2 10 0 17 19 1
13 3 0 3 18 1 4 10
1 7 2 0 6 13 12 8
2 19 13 11 0 1 10 8
0 18 3 16 0 0 5 19
1 6 17 19 15 6 0 0
4 4 14 18 4 19 0 0