source_code: import java.util.ArrayList;
  import java.util.Collections;
  import java.util.Scanner;
  
  
  public class LittleElephant {
  	public static void main(String[] args){
  		Scanner input = new Scanner(System.in);
  		int n = input.nextInt(); 
  		int temp;
  		ArrayList<Integer> a2 = new ArrayList<Integer>();
  		ArrayList<Integer> a1 = new ArrayList<Integer>();
  		int count = 0;
  		int temp1,temp2;
  		
  		for(int i= 0; i < n ; i++){
  			temp = input.nextInt();
  			a2.add(temp);
  			a1.add(temp);
  		}
  		Collections.sort(a2);
  		input.close();
  		for(int i = 0; i < n; i++){
  			temp1 = a2.get(i);
  			temp2 = a1.get(i);
  			if(temp1 != temp2){
  				count++;
  			}
  		}
  		if(count==2 || count==0){
  			System.out.println("YES");
  		}else{
  			System.out.println("NO");
  		}
  	}
  }
  