Plan 9 from Bell Labs’s /usr/web/sources/plan9/sys/games/lib/sudoku/boards/medium-2005-05-16.su
9...153.. 6..4..... ...9..5.4 54.1..6.. 7.......5 ..3..8.42 4.8..3... .....1..9 ..956...1 924815367 651437928 837926514 542179683 786342195 193658742 418793256 365281479 279564831