ref: 5fc5c18208546c77f2c279f7f6acf6b01a2d2645
dir: /sys/games/lib/sudoku/boards/easy-2005-01-30.su/
5.2..9.4. 3...4.... .7.5.3.9. 7.6.98... ..4...1.. ...17.8.4 .5.9.1.3. ....8...6 .2.3..7.8 562819347 391746285 478523691 716498523 284635179 935172864 857961432 143287956 629354718