1, 2, 3, 4, 5, 6, 12, 13, 14, 15, 16, 16, 21, 22, 23, 24,25, 26, 31, 32, 33, 34, 35, 36, 41, 42, 43, 44, 45, 46, 51, 52, 53, 54, 55, 56, 61, 62, 63, 64, 65, 66, 71, 72, 73, 74