401367: GYM100418 G String generator 2

You are given a sequence of integer numbers B. You should find the lexicographically smallest sequence A, consisting of the numbers from B, for which there is no i (1 ≤ i < |A|) such that A_i = A_i + 1. You can use each number from B only once.

The first line of the input contains a single integer number N (1 ≤ N ≤ 10⁶). The second line contains N integer numbers B_i separated by spaces (1 ≤ B_i ≤ 10⁶).

Output a sequence A which satisfies specified conditions. Output  - 1 if such sequence does not exist.

5
2 3 1 3 1

1 2 3 1 3