6 1 0 0 0 3 0 7 0 7 0 0 0 0 0 0 0 0 0 0 5 1 0 0 2 0 9 3 0 9 0 0 0 0 4 0 0 0 0 0 3 9 5 0 0 0 0 6 2 4 8 1 0 0 0 0 8 0 0 1 0 0 0 9 0 7 4 0 0 3 0 1 0 0 0 3 0 5 4 0 0 // source: www.zeit.de/sudoku (Sep 10, 2007, medium)