ref: ad7120b2e2f0ed0d226eec1b5ef6fc6b3eebb4ef
dir: /sys/games/lib/sudoku/boards/medium-2005-05-03.su/
45.2..... ....8.4.5 ..2..1.78 ....2...4 .4.7.9.8. 2...3.... 89.3..6.. 1.3.5.... .....8.57 458297136 719683425 362541978 936825714 541769283 287134569 895372641 173456892 624918357