ref: e77fa31516bc5dc834f1caf1f4ed3d888a9aa810
dir: /sys/games/lib/sudoku/boards/vhard-2005-03-25.su/
8.7.2.3.. .....34.. .5.....62 ...51...7 1...4...9 7...38... 59.....8. ..23..... ..1.5.9.4 867425391 219763458 453189762 936512847 128647539 745938216 594271683 682394175 371856924