ref: bf2a6f786502026ce4229bc84a6a22e5e55a7c13
dir: /sys/games/lib/sudoku/boards/medium002.su/
.4.....5. ..19436.. ..9...3.. 6...5...2 1.3...5.6 8...2...7 ..5...2.. ..24367.. .3.....4. 348267951 571943628 269185374 697351482 123874596 854629137 415798263 982436715 736512849