import java.util.Scanner;
class Main{


	static char[][] map;

	static long[][] c;
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);			//文字の入力
		int n = sc.nextInt();
		int[] p = new int[n];
		for(int i = 0;i < n;i++){
			p[i] = sc.nextInt();
			
		}
		if(check(p)){
			System.out.println("YES");
			return;
		}
		for(int i= 0;i < n;i++){
			
			for(int j = i + 1;j < n;j++){
				int[] cc = p.clone();
				cc[i] = p[j];
				cc[j] = p[i];
				if(check(cc)){
					System.out.println("YES");
					return;
				}
			}
		}
		System.out.println("NO");


		
	}
	static boolean check(int[] cc){
		for(int i = 0;i < cc.length-1;i++){
			if(cc[i] > cc[i+1]){
				return false;
			}
		}
		return true;
	}



	static int gcd(int a,int b){				//最大公約数を返す
		if(b == 0){
			return a;
		}else{
			return gcd(b, a%b);
		}
	}
	static long gcd(long a,long b){
		if(b == 0){
			return a;
		}else{
			return gcd(b, a%b);
		}
	}



	static long lcm (long a, long b) {
		long g = gcd(a,b);
		return a/g*b;
	}




}



class Pair implements Comparable{
	int from;
	int end;
	@Override
	public int compareTo(Object other) {
		Pair otherpair = (Pair)other;

		return   end- otherpair.end;
	}








}



 import java.util.Scanner; Scanner java.util class Main{


	static char[][] map;

	static long[][] c;
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);			//文字の入力
		int n = sc.nextInt();
		int[] p = new int[n];
		for(int i = 0;i < n;i++){
			p[i] = sc.nextInt();
			
		}
		if(check(p)){
			System.out.println("YES");
			return;
		}
		for(int i= 0;i < n;i++){
			
			for(int j = i + 1;j < n;j++){
				int[] cc = p.clone();
				cc[i] = p[j];
				cc[j] = p[i];
				if(check(cc)){
					System.out.println("YES");
					return;
				}
			}
		}
		System.out.println("NO");


		
	}
	static boolean check(int[] cc){
		for(int i = 0;i < cc.length-1;i++){
			if(cc[i] > cc[i+1]){
				return false;
			}
		}
		return true;
	}



	static int gcd(int a,int b){				//最大公約数を返す
		if(b == 0){
			return a;
		}else{
			return gcd(b, a%b);
		}
	}
	static long gcd(long a,long b){
		if(b == 0){
			return a;
		}else{
			return gcd(b, a%b);
		}
	}



	static long lcm (long a, long b) {
		long g = gcd(a,b);
		return a/g*b;
	}




} Main static char[][] map; map static long[][] c; c public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);			//文字の入力
		int n = sc.nextInt();
		int[] p = new int[n];
		for(int i = 0;i < n;i++){
			p[i] = sc.nextInt();
			
		}
		if(check(p)){
			System.out.println("YES");
			return;
		}
		for(int i= 0;i < n;i++){
			
			for(int j = i + 1;j < n;j++){
				int[] cc = p.clone();
				cc[i] = p[j];
				cc[j] = p[i];
				if(check(cc)){
					System.out.println("YES");
					return;
				}
			}
		}
		System.out.println("NO");


		
	} main {
		Scanner sc = new Scanner(System.in);			//文字の入力
		int n = sc.nextInt();
		int[] p = new int[n];
		for(int i = 0;i < n;i++){
			p[i] = sc.nextInt();
			
		}
		if(check(p)){
			System.out.println("YES");
			return;
		}
		for(int i= 0;i < n;i++){
			
			for(int j = i + 1;j < n;j++){
				int[] cc = p.clone();
				cc[i] = p[j];
				cc[j] = p[i];
				if(check(cc)){
					System.out.println("YES");
					return;
				}
			}
		}
		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 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 if(check(p)){
			System.out.println("YES");
			return;
		} check(p) check p {
			System.out.println("YES");
			return;
		} System.out.println("YES") System.out.println System.out System System.out "YES" return; for(int i= 0;i < n;i++){
			
			for(int j = i + 1;j < n;j++){
				int[] cc = p.clone();
				cc[i] = p[j];
				cc[j] = p[i];
				if(check(cc)){
					System.out.println("YES");
					return;
				}
			}
		} int i= 0; int i= 0; i 0 i < n i n i++ i++ i {
			
			for(int j = i + 1;j < n;j++){
				int[] cc = p.clone();
				cc[i] = p[j];
				cc[j] = p[i];
				if(check(cc)){
					System.out.println("YES");
					return;
				}
			}
		} {
			
			for(int j = i + 1;j < n;j++){
				int[] cc = p.clone();
				cc[i] = p[j];
				cc[j] = p[i];
				if(check(cc)){
					System.out.println("YES");
					return;
				}
			}
		} for(int j = i + 1;j < n;j++){
				int[] cc = p.clone();
				cc[i] = p[j];
				cc[j] = p[i];
				if(check(cc)){
					System.out.println("YES");
					return;
				}
			} int j = i + 1; int j = i + 1; j i + 1 i 1 j < n j n j++ j++ j {
				int[] cc = p.clone();
				cc[i] = p[j];
				cc[j] = p[i];
				if(check(cc)){
					System.out.println("YES");
					return;
				}
			} {
				int[] cc = p.clone();
				cc[i] = p[j];
				cc[j] = p[i];
				if(check(cc)){
					System.out.println("YES");
					return;
				}
			} int[] cc = p.clone(); cc p.clone() p.clone p cc[i] = p[j] cc[i] cc i p[j] p j cc[j] = p[i] cc[j] cc j p[i] p i if(check(cc)){
					System.out.println("YES");
					return;
				} check(cc) check cc {
					System.out.println("YES");
					return;
				} System.out.println("YES") System.out.println System.out System System.out "YES" return; System.out.println("NO") System.out.println System.out System System.out "NO" String[] args args static boolean check(int[] cc){
		for(int i = 0;i < cc.length-1;i++){
			if(cc[i] > cc[i+1]){
				return false;
			}
		}
		return true;
	} check {
		for(int i = 0;i < cc.length-1;i++){
			if(cc[i] > cc[i+1]){
				return false;
			}
		}
		return true;
	} for(int i = 0;i < cc.length-1;i++){
			if(cc[i] > cc[i+1]){
				return false;
			}
		} int i = 0; int i = 0; i 0 i < cc.length-1 i cc.length-1 cc.length cc cc.length 1 i++ i++ i {
			if(cc[i] > cc[i+1]){
				return false;
			}
		} {
			if(cc[i] > cc[i+1]){
				return false;
			}
		} if(cc[i] > cc[i+1]){
				return false;
			} cc[i] > cc[i+1] cc[i] cc i cc[i+1] cc i+1 i 1 {
				return false;
			} return false; false return true; true int[] cc cc static int gcd(int a,int b){				//最大公約数を返す
		if(b == 0){
			return a;
		}else{
			return gcd(b, a%b);
		}
	} gcd {				//最大公約数を返す
		if(b == 0){
			return a;
		}else{
			return gcd(b, a%b);
		}
	} if(b == 0){
			return a;
		}else{
			return gcd(b, a%b);
		} b == 0 b 0 {
			return a;
		} return a; a {
			return gcd(b, a%b);
		} return gcd(b, a%b); gcd(b, a%b) gcd b a%b a b int a a int b b static long gcd(long a,long b){
		if(b == 0){
			return a;
		}else{
			return gcd(b, a%b);
		}
	} gcd {
		if(b == 0){
			return a;
		}else{
			return gcd(b, a%b);
		}
	} if(b == 0){
			return a;
		}else{
			return gcd(b, a%b);
		} b == 0 b 0 {
			return a;
		} return a; a {
			return gcd(b, a%b);
		} return gcd(b, a%b); gcd(b, a%b) gcd b a%b a b long a a long b b static long lcm (long a, long b) {
		long g = gcd(a,b);
		return a/g*b;
	} lcm {
		long g = gcd(a,b);
		return a/g*b;
	} long g = gcd(a,b); g gcd(a,b) gcd a b return a/g*b; a/g*b a/g a g b long a a long b b class Pair implements Comparable{
	int from;
	int end;
	@Override
	public int compareTo(Object other) {
		Pair otherpair = (Pair)other;

		return   end- otherpair.end;
	}








} Pair int from; from int end; end @Override
	public int compareTo(Object other) {
		Pair otherpair = (Pair)other;

		return   end- otherpair.end;
	} compareTo {
		Pair otherpair = (Pair)other;

		return   end- otherpair.end;
	} Pair otherpair = (Pair)other; otherpair (Pair)other return   end- otherpair.end; end- otherpair.end end otherpair.end otherpair otherpair.end Object other other Comparable
import java.util.Scanner;
class Main{


	static char[][] map;

	static long[][] c;
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);			//文字の入力
		int n = sc.nextInt();
		int[] p = new int[n];
		for(int i = 0;i < n;i++){
			p[i] = sc.nextInt();
			
		}
		if(check(p)){
			System.out.println("YES");
			return;
		}
		for(int i= 0;i < n;i++){
			
			for(int j = i + 1;j < n;j++){
				int[] cc = p.clone();
				cc[i] = p[j];
				cc[j] = p[i];
				if(check(cc)){
					System.out.println("YES");
					return;
				}
			}
		}
		System.out.println("NO");


		
	}
	static boolean check(int[] cc){
		for(int i = 0;i < cc.length-1;i++){
			if(cc[i] > cc[i+1]){
				return false;
			}
		}
		return true;
	}



	static int gcd(int a,int b){				//最大公約数を返す
		if(b == 0){
			return a;
		}else{
			return gcd(b, a%b);
		}
	}
	static long gcd(long a,long b){
		if(b == 0){
			return a;
		}else{
			return gcd(b, a%b);
		}
	}



	static long lcm (long a, long b) {
		long g = gcd(a,b);
		return a/g*b;
	}




}



class Pair implements Comparable{
	int from;
	int end;
	@Override
	public int compareTo(Object other) {
		Pair otherpair = (Pair)other;

		return   end- otherpair.end;
	}








}




