ref: ff2ebe6cfdacd890a74a6d2f9b0acd062d2633b7
dir: /sys/games/lib/sudoku/boards/easy-2005-02-03.su/
.768..... ......2.6 ...96..58 .59..13.. 3..759..2 ..83..94. 94..38... 6.3...... .....463. 576812493 891543276 432967158 259481367 364759812 718326945 947638521 623195784 185274639