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