import java.util.*;
public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] p = new int[n];
		int[] firstP = new int[n];
		for(int i=0;i<n;i++){
			p[i] = sc.nextInt();
		}
		sc.close();
		
		for(int i=0;i<n;i++){
			firstP[i] = p[i];
		}
		
		Arrays.sort(p);
		
		int count = 0;
		
		for(int i=0;i<n;i++){
			if(p[i]!=firstP[i]){
				count++;
			}
		}
		if(count==0||count==2){
			System.out.println("YES");
		}else{
			System.out.println("NO");
		}
	}
} import java.util.*; util.* java public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] p = new int[n];
		int[] firstP = new int[n];
		for(int i=0;i<n;i++){
			p[i] = sc.nextInt();
		}
		sc.close();
		
		for(int i=0;i<n;i++){
			firstP[i] = p[i];
		}
		
		Arrays.sort(p);
		
		int count = 0;
		
		for(int i=0;i<n;i++){
			if(p[i]!=firstP[i]){
				count++;
			}
		}
		if(count==0||count==2){
			System.out.println("YES");
		}else{
			System.out.println("NO");
		}
	}
} Main public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] p = new int[n];
		int[] firstP = new int[n];
		for(int i=0;i<n;i++){
			p[i] = sc.nextInt();
		}
		sc.close();
		
		for(int i=0;i<n;i++){
			firstP[i] = p[i];
		}
		
		Arrays.sort(p);
		
		int count = 0;
		
		for(int i=0;i<n;i++){
			if(p[i]!=firstP[i]){
				count++;
			}
		}
		if(count==0||count==2){
			System.out.println("YES");
		}else{
			System.out.println("NO");
		}
	} main {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] p = new int[n];
		int[] firstP = new int[n];
		for(int i=0;i<n;i++){
			p[i] = sc.nextInt();
		}
		sc.close();
		
		for(int i=0;i<n;i++){
			firstP[i] = p[i];
		}
		
		Arrays.sort(p);
		
		int count = 0;
		
		for(int i=0;i<n;i++){
			if(p[i]!=firstP[i]){
				count++;
			}
		}
		if(count==0||count==2){
			System.out.println("YES");
		}else{
			System.out.println("NO");
		}
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc int[] p = new int[n]; p new int[n] n int[] firstP = new int[n]; firstP new int[n] n for(int i=0;i<n;i++){
			p[i] = sc.nextInt();
		} int i=0; int i=0; i 0 i<n i n i++ i++ i {
			p[i] = sc.nextInt();
		} {
			p[i] = sc.nextInt();
		} p[i] = sc.nextInt() p[i] p i sc.nextInt() sc.nextInt sc sc.close() sc.close sc for(int i=0;i<n;i++){
			firstP[i] = p[i];
		} int i=0; int i=0; i 0 i<n i n i++ i++ i {
			firstP[i] = p[i];
		} {
			firstP[i] = p[i];
		} firstP[i] = p[i] firstP[i] firstP i p[i] p i Arrays.sort(p) Arrays.sort Arrays p int count = 0; count 0 for(int i=0;i<n;i++){
			if(p[i]!=firstP[i]){
				count++;
			}
		} int i=0; int i=0; i 0 i<n i n i++ i++ i {
			if(p[i]!=firstP[i]){
				count++;
			}
		} {
			if(p[i]!=firstP[i]){
				count++;
			}
		} if(p[i]!=firstP[i]){
				count++;
			} p[i]!=firstP[i] p[i] p i firstP[i] firstP i {
				count++;
			} count++ count if(count==0||count==2){
			System.out.println("YES");
		}else{
			System.out.println("NO");
		} count==0||count==2 count==0 count 0 count==2 count 2 {
			System.out.println("YES");
		} System.out.println("YES") System.out.println System.out System System.out "YES" {
			System.out.println("NO");
		} System.out.println("NO") System.out.println System.out System System.out "NO" String[] args args public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] p = new int[n];
		int[] firstP = new int[n];
		for(int i=0;i<n;i++){
			p[i] = sc.nextInt();
		}
		sc.close();
		
		for(int i=0;i<n;i++){
			firstP[i] = p[i];
		}
		
		Arrays.sort(p);
		
		int count = 0;
		
		for(int i=0;i<n;i++){
			if(p[i]!=firstP[i]){
				count++;
			}
		}
		if(count==0||count==2){
			System.out.println("YES");
		}else{
			System.out.println("NO");
		}
	}
} public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] p = new int[n];
		int[] firstP = new int[n];
		for(int i=0;i<n;i++){
			p[i] = sc.nextInt();
		}
		sc.close();
		
		for(int i=0;i<n;i++){
			firstP[i] = p[i];
		}
		
		Arrays.sort(p);
		
		int count = 0;
		
		for(int i=0;i<n;i++){
			if(p[i]!=firstP[i]){
				count++;
			}
		}
		if(count==0||count==2){
			System.out.println("YES");
		}else{
			System.out.println("NO");
		}
	}
} Main
import java.util.*;
public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] p = new int[n];
		int[] firstP = new int[n];
		for(int i=0;i<n;i++){
			p[i] = sc.nextInt();
		}
		sc.close();
		
		for(int i=0;i<n;i++){
			firstP[i] = p[i];
		}
		
		Arrays.sort(p);
		
		int count = 0;
		
		for(int i=0;i<n;i++){
			if(p[i]!=firstP[i]){
				count++;
			}
		}
		if(count==0||count==2){
			System.out.println("YES");
		}else{
			System.out.println("NO");
		}
	}
}
