ref: 94d2ee527af44610a498d6f6adbba8f0b6d76f17
dir: /sys/games/lib/sudoku/boards/easy-2005-02-02.su/
8....5.3. ..63.1..8 .3978.... .9.53.1.. 5..4.8..9 ..7.16.8. ....4375. 1..8.74.. .7.1....6 814265937 756391248 239784615 698532174 521478369 347916582 982643751 165827493 473159826