ref: ea993877a96cd535199d0cd437e49f8d616615d9
dir: /sys/games/lib/sudoku/boards/vhard-2005-03-20.su/
1..92.... 524.1.... .......7. .5...81.2 ......... 4.27...9. .6....... ....3.945 ....71..6 176923584 524817639 893654271 957348162 638192457 412765398 265489713 781236945 349571826