ref: 0541a434cb9cfd1a776f1ef29de3a8a7aa1d9b99
dir: /sys/games/lib/sudoku/boards/easy-2005-03-12.su/
.9..1.2.. ..8.96..3 3..8...49 .7..3.... .5.2.7.9. ....5..8. 42...5..6 5..36.7.. ..7.2..1. 794513268 218496573 365872149 976138452 853247691 142659387 421785936 589361724 637924815