Problem Statement

We have a sequence $p$ = {$p_1,\ p_2,\ ...,\ p_N$} which is a permutation of {$1,\ 2,\ ...,\ N$}.

You can perform the following operation at most once: choose integers $i$ and $j$ $(1 \leq i < j \leq N)$, and swap $p_i$ and $p_j$. Note that you can also choose not to perform it.

Print YES if you can sort $p$ in ascending order in this way, and NO otherwise.

Constraints

• All values in input are integers.
• $2 \leq N \leq 50$
• $p$ is a permutation of {$1,\ 2,\ ...,\ N$}.

Input

Input is given from Standard Input in the following format:

N
p_1 p_2 ... p_N

Output

Print YES if you can sort $p$ in ascending order in the way stated in the problem statement, and NO otherwise.