ref: 63f9a4fda36f916e543c8f3ea117b31c194a4db7
dir: /sys/games/lib/sudoku/boards/easy-2005-03-03.su/
7...28..5 ..6...... .4..16.82 .6....79. 4.2...6.1 .73....5. 53.49..7. ......5.. 8..67...3 719328465 286549317 345716982 168253794 452987631 973164258 531492876 627831549 894675123