ref: e7a3cd0fd0f41e03f7b861d5e092f8a4a51f5fa8
dir: /sys/games/lib/sudoku/boards/medium-2005-02-24.su/
..12..5.9 34.....82 ....79... 75.9..... .2.....9. .....4.67 ...83.... 43.....71 9.2..63.. 671283549 349615782 285479136 756928413 124367895 893154267 567831924 438592671 912746358