import java.util.*;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);

        int N = sc.nextInt();
        int ans = 0;

        for(int i=1; i<=N; i++){
            if(i!=sc.nextInt()){
                ans += 1;
            }
        }
        if(ans<=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 ans = 0;

        for(int i=1; i<=N; i++){
            if(i!=sc.nextInt()){
                ans += 1;
            }
        }
        if(ans<=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 ans = 0;

        for(int i=1; i<=N; i++){
            if(i!=sc.nextInt()){
                ans += 1;
            }
        }
        if(ans<=2){
            System.out.println("YES");
        }
        else{
            System.out.println("NO");
        }
    } main {
        Scanner sc = new Scanner(System.in);

        int N = sc.nextInt();
        int ans = 0;

        for(int i=1; i<=N; i++){
            if(i!=sc.nextInt()){
                ans += 1;
            }
        }
        if(ans<=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 ans = 0; ans 0 for(int i=1; i<=N; i++){
            if(i!=sc.nextInt()){
                ans += 1;
            }
        } int i=1; int i=1; i 1 i<=N i N i++ i++ i {
            if(i!=sc.nextInt()){
                ans += 1;
            }
        } {
            if(i!=sc.nextInt()){
                ans += 1;
            }
        } if(i!=sc.nextInt()){
                ans += 1;
            } i!=sc.nextInt() i sc.nextInt() sc.nextInt sc {
                ans += 1;
            } ans += 1 ans 1 if(ans<=2){
            System.out.println("YES");
        }
        else{
            System.out.println("NO");
        } ans<=2 ans 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 ans = 0;

        for(int i=1; i<=N; i++){
            if(i!=sc.nextInt()){
                ans += 1;
            }
        }
        if(ans<=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 ans = 0;

        for(int i=1; i<=N; i++){
            if(i!=sc.nextInt()){
                ans += 1;
            }
        }
        if(ans<=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 ans = 0;

        for(int i=1; i<=N; i++){
            if(i!=sc.nextInt()){
                ans += 1;
            }
        }
        if(ans<=2){
            System.out.println("YES");
        }
        else{
            System.out.println("NO");
        }
    }
}