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

0 0 0  8 0 3  0 0 0
0 0 7  0 0 0  5 0 0
0 0 0  2 0 6  0 0 0

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

CTC extreme
look for box/row/col doubles
multiple Xcycles + F solves
