[[x, 4, x, x, x, x, x, 9, x],
 [x, 9, 7, 1, x, 8, 2, 3, x],
 [8, x, 2, x, x, x, 5, x, 7],
 [x, x, x, 3, 8, 4, x, x, x],
 [x, x, x, x, 5, x, x, x, x],
 [x, x, x, 6, 1, 2, x, x, x],
 [6, x, 4, x, x, x, 3, x, 9],
 [x, 1, 3, 4, x, 5, 6, 8, x],
 [x, 2, x, x, x, x, x, 4, x]]