ref: 23620bb1dbbf80f07a156d3f1fe1e74d5f4d61ba
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