ref: 88b9bda96cc4188f12713c2f5cb089f13bc8d368
dir: /sys/games/lib/sudoku/boards/easy-2005-04-28.su/
.9.3.7..2 .4..1.... ..19..53. ...7.1..8 96.....73 8..6.3... .28..93.. ....6..8. 4..8.5.9. 695387412 743512869 281946537 354791628 962458173 817623954 528179346 139264785 476835291