
import java.util.*;

public class Main {
	public static void main(String[] args) {
		Main main = new Main();
		main.run();
	}

	public void run() {
		Scanner sc = new Scanner(System.in);
		int n=sc.nextInt();
		int p[] =new int[n];

		int cnt=0;
		for(int i=0; i<n; i++) {
			p[i]=sc.nextInt();

		}
		for(int i=0; i<n; i++) {
			if(p[i] != i+1) cnt++;
		}

		if(cnt<=2) {
			System.out.println("YES");
		}else {
			System.out.println("NO");
		}
		sc.close();
	}
} import java.util.*; util.* java public class Main {
	public static void main(String[] args) {
		Main main = new Main();
		main.run();
	}

	public void run() {
		Scanner sc = new Scanner(System.in);
		int n=sc.nextInt();
		int p[] =new int[n];

		int cnt=0;
		for(int i=0; i<n; i++) {
			p[i]=sc.nextInt();

		}
		for(int i=0; i<n; i++) {
			if(p[i] != i+1) cnt++;
		}

		if(cnt<=2) {
			System.out.println("YES");
		}else {
			System.out.println("NO");
		}
		sc.close();
	}
} Main public static void main(String[] args) {
		Main main = new Main();
		main.run();
	} main {
		Main main = new Main();
		main.run();
	} Main main = new Main(); main new Main() main.run() main.run main String[] args args public void run() {
		Scanner sc = new Scanner(System.in);
		int n=sc.nextInt();
		int p[] =new int[n];

		int cnt=0;
		for(int i=0; i<n; i++) {
			p[i]=sc.nextInt();

		}
		for(int i=0; i<n; i++) {
			if(p[i] != i+1) cnt++;
		}

		if(cnt<=2) {
			System.out.println("YES");
		}else {
			System.out.println("NO");
		}
		sc.close();
	} run {
		Scanner sc = new Scanner(System.in);
		int n=sc.nextInt();
		int p[] =new int[n];

		int cnt=0;
		for(int i=0; i<n; i++) {
			p[i]=sc.nextInt();

		}
		for(int i=0; i<n; i++) {
			if(p[i] != i+1) cnt++;
		}

		if(cnt<=2) {
			System.out.println("YES");
		}else {
			System.out.println("NO");
		}
		sc.close();
	} 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 cnt=0; cnt 0 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 for(int i=0; i<n; i++) {
			if(p[i] != i+1) cnt++;
		} int i=0; int i=0; i 0 i<n i n i++ i++ i {
			if(p[i] != i+1) cnt++;
		} {
			if(p[i] != i+1) cnt++;
		} if(p[i] != i+1) cnt++; p[i] != i+1 p[i] p i i+1 i 1 cnt++ cnt if(cnt<=2) {
			System.out.println("YES");
		}else {
			System.out.println("NO");
		} cnt<=2 cnt 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" sc.close() sc.close sc public class Main {
	public static void main(String[] args) {
		Main main = new Main();
		main.run();
	}

	public void run() {
		Scanner sc = new Scanner(System.in);
		int n=sc.nextInt();
		int p[] =new int[n];

		int cnt=0;
		for(int i=0; i<n; i++) {
			p[i]=sc.nextInt();

		}
		for(int i=0; i<n; i++) {
			if(p[i] != i+1) cnt++;
		}

		if(cnt<=2) {
			System.out.println("YES");
		}else {
			System.out.println("NO");
		}
		sc.close();
	}
} public class Main {
	public static void main(String[] args) {
		Main main = new Main();
		main.run();
	}

	public void run() {
		Scanner sc = new Scanner(System.in);
		int n=sc.nextInt();
		int p[] =new int[n];

		int cnt=0;
		for(int i=0; i<n; i++) {
			p[i]=sc.nextInt();

		}
		for(int i=0; i<n; i++) {
			if(p[i] != i+1) cnt++;
		}

		if(cnt<=2) {
			System.out.println("YES");
		}else {
			System.out.println("NO");
		}
		sc.close();
	}
} Main

import java.util.*;

public class Main {
	public static void main(String[] args) {
		Main main = new Main();
		main.run();
	}

	public void run() {
		Scanner sc = new Scanner(System.in);
		int n=sc.nextInt();
		int p[] =new int[n];

		int cnt=0;
		for(int i=0; i<n; i++) {
			p[i]=sc.nextInt();

		}
		for(int i=0; i<n; i++) {
			if(p[i] != i+1) cnt++;
		}

		if(cnt<=2) {
			System.out.println("YES");
		}else {
			System.out.println("NO");
		}
		sc.close();
	}
}
