#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int a[n], b[n], cntr = 0;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    b[i] = a[i];
  }
  sort(b, b + n);
  for (int i = 0; i < n; i++)
    if (a[i] != b[i]) cntr++;
  if (cntr <= 2)
    cout << "YES\n";
  else
    cout << "NO\n";
}
