2, 6, 7, 8
2, 6, 7, 8, 1, 10, 12, 18, 2, 4, 6, 8
2, 6, 7, 8, 1, 10, 12, 18, 2, 4, 6, 8, 1, 10, 3, 4, 5, 6, 7, 8, 9