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