10 5
1 0 6 0 2
20 20 5 0 0
3 4 5 4 3
0 0 6 0 1
2 7 7 9 9
11 0 16 0 12
0 0 15 0 0
13 14 15 14 13
0 0 16 0 11
12 17 17 19 19