ref: 9cf3dc9a259cadc80e6d3840c658ef1d5f7c94a4
dir: /sys/games/lib/sudoku/boards/medium-2005-04-14.su/
....1..32 .....36.. .37..8... .7.8..1.5 .25.6.94. 9.6..4.7. ...4..89. ..93..... 24..9.... 584916732 192753684 637248519 473829165 825167943 916534278 351472896 769385421 248691357