0 2 0   0 0 0   0 0 0
0 0 0   6 0 0   0 0 3
0 7 4   0 8 0   0 0 0

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

0 0 0   0 1 0   7 8 0
5 0 0   0 0 9   0 0 0
0 0 0   0 0 0   0 4 0
