ref: 1f95e98dddc420321a8942d9f3195d966c7cc6c0
dir: /sys/games/lib/sudoku/boards/easy-2005-02-07.su/
.1..59..2 ..42..5.. ..2...671 4..3..76. ....2.... .65..7..3 146...3.. ..8..34.. 7..64..5. 613759842 874261539 592834671 421398765 387526914 965417283 146985327 258173496 739642158