Plan 9 from Bell Labs’s /usr/web/sources/plan9/sys/games/lib/sudoku/boards/medium-2005-04-27.su
.5...61.. .243..... 1......67 36...9... ..1...2.. ...5...76 47......9 .....458. ..51...4. 753986124 624371895 189452367 367829451 591647238 842513976 478235619 216794583 935168742