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