source_code: import java.util.*;
  public class r220a {
  	public static void main(String args[]) {
  		Scanner in =new Scanner(System.in);
  		int N = in.nextInt();
  		ArrayList<Integer> list = new ArrayList<Integer>();
  		ArrayList<Integer> sort = new ArrayList<Integer>();
  		for(int i = 0; i < N; i++) {
  			int k = in.nextInt();
  			list.add(k);
  			sort.add(k);
  		}
  		
  		Collections.sort(sort);
  		
  		int count = 0;
  		for(int i = 0; i < N; i++) {
  			if(sort.get(i).intValue() != list.get(i).intValue())
  				count++;
  		}
  		if(count != 2 && count != 0)
  			System.out.println("NO");
  		else
  			System.out.println("YES");
  	}
  }
  