ref: cb474632d3f23de10fea2d70a4b4c98d8f3a3755
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