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

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

6 x x x 7 x x 5 1
x x 1 6 5 x 8 x x
5 x x 9 8 1 4 6 3