9 21 7
1 1 1 1 1 1 7 4 2 2 1 5 7 6 3 3 3 1 3 5 4
0 0 0 2 0 0 0 0 0
0 4 0 0 0 0 0 0 0
0 0 0 0 0 7 3 0 0
0 6 0 4 0 0 0 0 3
0 0 0 3 0 0 0 0 0
0 0 0 0 0 0 0 7 0
0 0 0 0 0 0 1 0 5
0 0 1 0 0 0 0 1 2
0 0 0 0 5 0 3 0 0
