ref: cb091e75393b176ccb02c68f0ecfcfbb8bc49376
dir: /sys/games/lib/sudoku/boards/easy-2005-04-11.su/
..5..6..2 ..21..... .14..7... 4..6..32. 57.3.2.98 .38..1..4 ...7..25. .....38.. 6..2..7.. 785436912 362195487 914827563 491678325 576342198 238951674 843719256 127563849 659284731