import java.util.Scanner;

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

        int n = sc.nextInt();

        int cnt = 0;
        for (int i = 1; i <= n; i++) {
            int tmp = sc.nextInt();
            if (i != tmp)
                cnt++;
        }

        if (cnt <= 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 cnt = 0;
        for (int i = 1; i <= n; i++) {
            int tmp = sc.nextInt();
            if (i != tmp)
                cnt++;
        }

        if (cnt <= 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 cnt = 0;
        for (int i = 1; i <= n; i++) {
            int tmp = sc.nextInt();
            if (i != tmp)
                cnt++;
        }

        if (cnt <= 2)
            System.out.println("YES");
        else
            System.out.println("NO");
    } main {
        Scanner sc = new Scanner(System.in);

        int n = sc.nextInt();

        int cnt = 0;
        for (int i = 1; i <= n; i++) {
            int tmp = sc.nextInt();
            if (i != tmp)
                cnt++;
        }

        if (cnt <= 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 cnt = 0; cnt 0 for (int i = 1; i <= n; i++) {
            int tmp = sc.nextInt();
            if (i != tmp)
                cnt++;
        } int i = 1; int i = 1; i 1 i <= n i n i++ i++ i {
            int tmp = sc.nextInt();
            if (i != tmp)
                cnt++;
        } {
            int tmp = sc.nextInt();
            if (i != tmp)
                cnt++;
        } int tmp = sc.nextInt(); tmp sc.nextInt() sc.nextInt sc if (i != tmp)
                cnt++; i != tmp i tmp 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 System.out System System.out "YES" 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 cnt = 0;
        for (int i = 1; i <= n; i++) {
            int tmp = sc.nextInt();
            if (i != tmp)
                cnt++;
        }

        if (cnt <= 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 cnt = 0;
        for (int i = 1; i <= n; i++) {
            int tmp = sc.nextInt();
            if (i != tmp)
                cnt++;
        }

        if (cnt <= 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 cnt = 0;
        for (int i = 1; i <= n; i++) {
            int tmp = sc.nextInt();
            if (i != tmp)
                cnt++;
        }

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