15, 2, 6, 8
15, 2, 6, 8, 3
15, 2, 6, 8, 3, 1, 2, 3
15, 2, 6, 8, 3, 1, 2, 3, 13, 15, 15/1, 19, 2, 20, 22, 23, 6, 68, 7, 9