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