ref: dc96f164a2b72ccb209ae98ce50a11087cbe44f8
dir: /sys/games/lib/sudoku/boards/easy-2005-03-09.su/
34...1..8 .56...... .1.82.... ..51...47 4..3.5..2 98...25.. ....48.5. ......28. 2..5...34 342651978 856794123 719823465 625189347 471365892 983472516 137248659 564937281 298516734