ref: 94d2ee527af44610a498d6f6adbba8f0b6d76f17
dir: /sys/games/lib/sudoku/boards/medium-2005-05-05.su/
35.8..6.. 2....4... ..92...87 ..1..8..5 .4.....9. 9..7..4.. 52...38.. ...5....2 ..6..7.13 357819624 218674359 469235187 731948265 642351798 985762431 524193876 173586942 896427513