ref: 4cd46e8601a04d2dc4fa91f95f5be4be14943c96
dir: /sys/games/lib/sudoku/boards/vhard-2005-05-08.su/
4...2.7.. ..5...63. ...8...9. 1...6...8 ...9.8... 2...4...3 .4...9... .63...2.. ..7.5...4 496325781 785194632 312876495 139762548 654938127 278541963 541289376 863417259 927653814