source_code: import java.io.BufferedReader;
  import java.io.File;
  import java.io.FileReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.io.PrintWriter;
  import java.util.Arrays;
  import java.util.Scanner;
  import java.util.StringTokenizer;
  
  public class C {
  	BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
  	StringTokenizer st = null;
  	PrintWriter out;
  
  	public void solution() throws IOException {
  		int n = nextInt();
  		int a[] = new int[n];
  		int b[] = new int[n];
  		for (int i = 0; i < n; i++) {
  			a[i] = nextInt();
  			b[i] = a[i];
  		}
  		Arrays.sort(a);
  		int ans = 0;
  		for (int i = 0; i < n; i++) {
  			if (a[i] != b[i]) {
  				ans++;
  			}
  		}
  
  		if (ans == 2 || ans == 0) {
  			System.out.println("YES");
  		} else {
  			System.out.println("NO");
  		}
  
  	}
  
  	public String nextToken() throws IOException {
  		if (st == null || !st.hasMoreTokens()) {
  			st = new StringTokenizer(bf.readLine());
  		}
  		return st.nextToken();
  	}
  
  	int nextInt() throws IOException {
  		return Integer.parseInt(nextToken());
  	}
  
  	long nextLong() throws IOException {
  		return Long.parseLong(nextToken());
  	}
  
  	double nextDouble() throws IOException {
  		return Double.parseDouble(nextToken());
  	}
  
  	public void print(int a[]) {
  		for (int i = 0; i < a.length; i++) {
  			System.out.print(a[i] + " ");
  		}
  	}
  
  	public static void main(String args[]) throws IOException {
  		new C().solution();
  	}
  }