1, 2, 3, 4 5, 6, 7, 8 9, 10, 11, 12 13, 14, 15, 16 17, 18, 19 20, 21, 22, 23 24, 25, 26, 27 28, 29, 30 31, 32, 33, 34 35, 36, 37, 38 39, 40, 41, 42