8
8, 1, 10, 11, 12, 13, 14, 15, 16, 17, 19, 2, 20, 21, 23, 25, 26, 28, 29, 3, 33, 34, 37, 38, 4, 41, 43, 44, 45, 46, 47, 48, 49, 5, 50, 51, 52, 53, 54, 55, 56, 6, 7, 9