1, 2, 3, 4
1, 2, 3, 4, 2, 3, 4, 5
1, 2, 3, 4, 2, 3, 4, 5, 1, 11, 13, 14, 15, 17, 18, 19, 2, 21, 23, 3, 4, 5, 7, 8