1, 4, 2, 5, 3, 8, 6, 9, 7, 12, 10, 13, 11, 16, 14, 17, 15, 20, 18, 21, 19, 24, 22, 25, 23, 28, 26, 29, 27, 32, 30, 33, 31, 36, 34, 37, 35, 40, 38, 41, 39, 44, 42, 45, 43, 48, 46, 49, 47, 52, 50, 53, 51, 56, 54, 57, 55, 60, 58, 61, 59, 64, 62, 65, 63, 68, 66, 69, 67, 72, 70, 73