source_code: import java.util.*;
  import java.io.*;
  import java.awt.Point;
  import static java.lang.Math.*;
  
  public class CF220A {
      public static void main(String[] args) throws Exception {
          BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
          int n = Integer.parseInt(in.readLine());
          StringTokenizer st = new StringTokenizer(in.readLine());
          int[] A = new int[n];
          Integer[] B = new Integer[n];
          for(int i=0; i<n; i++) {
              A[i] = Integer.parseInt(st.nextToken());
              B[i] = A[i];
          }
          Collections.sort(Arrays.asList(B));
  
          int cnt = 0;
          for(int i=0; i<n; i++)
              if(A[i] != B[i])
                  cnt++;
          System.out.println(cnt <= 2 ? "YES" : "NO");
      }
  }
  