import java.util.Scanner;
public class Main {
    public static void main(String[] args){
    
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    int[]a = new int[n];

    int cou = 0;
    for(int i=0; i<n; i++) {
    	a[i] = sc.nextInt();
    	if(a[i] != i+1) {
    		cou++;
    	}
    }   	
    if(cou<=2) {
    	System.out.println("YES");
    }else {
    	System.out.println("NO");
    }
    }
} import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args){
    
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    int[]a = new int[n];

    int cou = 0;
    for(int i=0; i<n; i++) {
    	a[i] = sc.nextInt();
    	if(a[i] != i+1) {
    		cou++;
    	}
    }   	
    if(cou<=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[]a = new int[n];

    int cou = 0;
    for(int i=0; i<n; i++) {
    	a[i] = sc.nextInt();
    	if(a[i] != i+1) {
    		cou++;
    	}
    }   	
    if(cou<=2) {
    	System.out.println("YES");
    }else {
    	System.out.println("NO");
    }
    } main {
    
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    int[]a = new int[n];

    int cou = 0;
    for(int i=0; i<n; i++) {
    	a[i] = sc.nextInt();
    	if(a[i] != i+1) {
    		cou++;
    	}
    }   	
    if(cou<=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[]a = new int[n]; a new int[n] n int cou = 0; cou 0 for(int i=0; i<n; i++) {
    	a[i] = sc.nextInt();
    	if(a[i] != i+1) {
    		cou++;
    	}
    } int i=0; int i=0; i 0 i<n i n i++ i++ i {
    	a[i] = sc.nextInt();
    	if(a[i] != i+1) {
    		cou++;
    	}
    } {
    	a[i] = sc.nextInt();
    	if(a[i] != i+1) {
    		cou++;
    	}
    } a[i] = sc.nextInt() a[i] a i sc.nextInt() sc.nextInt sc if(a[i] != i+1) {
    		cou++;
    	} a[i] != i+1 a[i] a i i+1 i 1 {
    		cou++;
    	} cou++ cou if(cou<=2) {
    	System.out.println("YES");
    }else {
    	System.out.println("NO");
    } cou<=2 cou 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[]a = new int[n];

    int cou = 0;
    for(int i=0; i<n; i++) {
    	a[i] = sc.nextInt();
    	if(a[i] != i+1) {
    		cou++;
    	}
    }   	
    if(cou<=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[]a = new int[n];

    int cou = 0;
    for(int i=0; i<n; i++) {
    	a[i] = sc.nextInt();
    	if(a[i] != i+1) {
    		cou++;
    	}
    }   	
    if(cou<=2) {
    	System.out.println("YES");
    }else {
    	System.out.println("NO");
    }
    }
} Main
import java.util.Scanner;
public class Main {
    public static void main(String[] args){
    
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    int[]a = new int[n];

    int cou = 0;
    for(int i=0; i<n; i++) {
    	a[i] = sc.nextInt();
    	if(a[i] != i+1) {
    		cou++;
    	}
    }   	
    if(cou<=2) {
    	System.out.println("YES");
    }else {
    	System.out.println("NO");
    }
    }
}