#include<cstdio>

int n,a[51],sum,i;

int main()
{
	scanf("%d",&n);
	for(i=0;i<n;i++)
	{
		scanf("%d",&a[i]);
		if(a[i]!=i+1)sum++;
	}
	if(sum<3)printf("YES");
	else printf("NO");
	return 0;
}
### Prompt

Create a solution in cpp for the following problem:

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.

Examples

Input

5
5 2 3 4 1


Output

YES


Input

5
2 4 3 5 1


Output

NO


Input

7
1 2 3 4 5 6 7


Output

YES

### Response

```cpp
#include<cstdio>

int n,a[51],sum,i;

int main()
{
	scanf("%d",&n);
	for(i=0;i<n;i++)
	{
		scanf("%d",&a[i]);
		if(a[i]!=i+1)sum++;
	}
	if(sum<3)printf("YES");
	else printf("NO");
	return 0;
}
```