ref: b7a4dab54ab89f9cd62f3a31166cff553450cd28
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