ref: 215b67ff3d630c56418026dda7ae68f23111c4a5
dir: /sys/games/lib/sudoku/boards/veasy001.su/
.5.8.7.2. 6...1..9. 7.254...6 .7..2.3.1 5.4...9.8 1.3.8..7. 9...762.5 .6..9...3 .8.1.3.4. 359867124 648312597 712549836 876924351 524731968 193685472 931476285 465298713 287153649