1
1, 2, 1
1, 2, 3, 2, 1
1, 2, 3, 4, 3, 2, 1
1, 2, 3, 4, 5, 4, 3, 2, 1
1, 2, 3, 4, 3, 2, 1
1, 2, 3, 2, 1
1, 2, 1
1

1
1, 2, 1
1, 2, 3, 2, 1
1, 2, 3, 4, 3, 2, 1
1, 2, 3, 4, 5, 4, 3, 2, 1
1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1
1, 2, 3, 4, 5, 4, 3, 2, 1
1, 2, 3, 4, 3, 2, 1
1, 2, 3, 2, 1
1, 2, 1
1

1
1, 2, 1
1, 2, 3, 2, 1
1, 2, 3, 4, 3, 2, 1
1, 2, 3, 4, 5, 4, 3, 2, 1
1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1
1, 2, 3, 4, 5, 6, 7, 6, 5, 4, 3, 2, 1
1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1
1, 2, 3, 4, 5, 4, 3, 2, 1
1, 2, 3, 4, 3, 2, 1
1, 2, 3, 2, 1
1, 2, 1
1

1
1, 2, 1
1, 2, 3, 2, 1
1, 2, 3, 4, 3, 2, 1
1, 2, 3, 4, 5, 4, 3, 2, 1
1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1
1, 2, 3, 4, 5, 6, 7, 6, 5, 4, 3, 2, 1
1, 2, 3, 4, 5, 6, 7, 8, 7, 6, 5, 4, 3, 2, 1
1, 2, 3, 4, 5, 6, 7, 6, 5, 4, 3, 2, 1
1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1
1, 2, 3, 4, 5, 4, 3, 2, 1
1, 2, 3, 4, 3, 2, 1
1, 2, 3, 2, 1
1, 2, 1
1