ref: 36c9a2489d1f0e3d4e6a890bb86edde64d719acb
dir: /sys/games/lib/sudoku/boards/hard-2005-05-19.su/
17.3..... ...1.48.. .34.29... 3........ ..72485.. ........6 ...87.92. ..25.1... .....2.85 175386492 926154873 834729651 359617248 617248539 248935716 561873924 482591367 793462185