ref: e0278f69176765b408be4f29e6f3e5d39b928601
dir: /sys/games/lib/sudoku/boards/easy001.su/
..35.29.. ....4.... 1.6...3.5 9..251..8 .7.4.8.3. 8..763..1 3.8...1.4 ....2.... ..51.48.. 743512986 589346217 126987345 934251768 671498532 852763491 398675124 417829653 265134879