输入描述:

There is only one input line; it contains two space separated integers: n (1 ≤ n ≤ 100), representing the number of nodes in the binary search tree, andk(1 ≤k≤ 1018), where we desire thekth lexicographical permutation of the first  nintegers which creates  a binary  search tree of height  n– 1, when inserted in the order given in the permutation.

输出描述:

Print thekth lexicographical permutation of the integers 1 throughnof the permutations which, when the values are inserted into a binary search tree, create a tree of heightn– 1. Output the permutation on a single line, following each number in the permutation with a space. If no such permutation exists, output –1 instead.

5 12

5 1 4 3 2

4 2

1 2 4 3

6 1

1 2 3 4 5 6

3 50

-1