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

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

0 0 0  0 0 4  6 0 0
7 0 0  8 0 0  0 0 0
0 0 9  0 3 0  0 0 0

weekly unsolvable #551
multiple KeyCells until solved
