C. Ehab and Prefix MEXs
time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output

Given an array $$$a$$$ of length $$$n$$$, find another array, $$$b$$$, of length $$$n$$$ such that:

  • for each $$$i$$$ $$$(1 \le i \le n)$$$ $$$MEX(\{b_1$$$, $$$b_2$$$, $$$\ldots$$$, $$$b_i\})=a_i$$$.

The $$$MEX$$$ of a set of integers is the smallest non-negative integer that doesn't belong to this set.

If such array doesn't exist, determine this.

Input

The first line contains an integer $$$n$$$ ($$$1 \le n \le 10^5$$$) — the length of the array $$$a$$$.

The second line contains $$$n$$$ integers $$$a_1$$$, $$$a_2$$$, $$$\ldots$$$, $$$a_n$$$ ($$$0 \le a_i \le i$$$) — the elements of the array $$$a$$$. It's guaranteed that $$$a_i \le a_{i+1}$$$ for $$$1\le i < n$$$.

Output

If there's no such array, print a single line containing $$$-1$$$.

Otherwise, print a single line containing $$$n$$$ integers $$$b_1$$$, $$$b_2$$$, $$$\ldots$$$, $$$b_n$$$ ($$$0 \le b_i \le 10^6$$$)

If there are multiple answers, print any.

Examples
Input
3
1 2 3
Output
0 1 2
Input
4
0 0 0 2
Output
1 3 4 0
Input
3
1 1 3
Output
0 2 1
Note

In the second test case, other answers like $$$[1,1,1,0]$$$, for example, are valid.