ref: 0a460e1722c50e31653359f8a86fe0b606d2b513
dir: /sys/games/lib/sudoku/boards/medium-2005-03-31.su/
....38... .76...... 28..9.... .6.8...43 8.16.39.5 79...1.2. ....8..92 ......43. ...95.... 159238764 376415289 284796351 562879143 841623975 793541826 617384592 925167438 438952617