import java.util.Scanner;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int[] p = new int[N + 1];
        int cnt = 0;
        for (int i = 1; i <= N; i++) {
            p[i] = sc.nextInt();
            if (p[i] != i) {
                cnt++;
            }
        }
        if (cnt < 3) {
            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) throws Exception {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int[] p = new int[N + 1];
        int cnt = 0;
        for (int i = 1; i <= N; i++) {
            p[i] = sc.nextInt();
            if (p[i] != i) {
                cnt++;
            }
        }
        if (cnt < 3) {
            System.out.println("YES");
        } else {
            System.out.println("NO");
        }
    }
} Main public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int[] p = new int[N + 1];
        int cnt = 0;
        for (int i = 1; i <= N; i++) {
            p[i] = sc.nextInt();
            if (p[i] != i) {
                cnt++;
            }
        }
        if (cnt < 3) {
            System.out.println("YES");
        } else {
            System.out.println("NO");
        }
    } main {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int[] p = new int[N + 1];
        int cnt = 0;
        for (int i = 1; i <= N; i++) {
            p[i] = sc.nextInt();
            if (p[i] != i) {
                cnt++;
            }
        }
        if (cnt < 3) {
            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[] p = new int[N + 1]; p new int[N + 1] N + 1 N 1 int cnt = 0; cnt 0 for (int i = 1; i <= N; i++) {
            p[i] = sc.nextInt();
            if (p[i] != i) {
                cnt++;
            }
        } int i = 1; int i = 1; i 1 i <= N i N i++ i++ i {
            p[i] = sc.nextInt();
            if (p[i] != i) {
                cnt++;
            }
        } {
            p[i] = sc.nextInt();
            if (p[i] != i) {
                cnt++;
            }
        } p[i] = sc.nextInt() p[i] p i sc.nextInt() sc.nextInt sc if (p[i] != i) {
                cnt++;
            } p[i] != i p[i] p i i {
                cnt++;
            } cnt++ cnt if (cnt < 3) {
            System.out.println("YES");
        } else {
            System.out.println("NO");
        } cnt < 3 cnt 3 {
            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) throws Exception {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int[] p = new int[N + 1];
        int cnt = 0;
        for (int i = 1; i <= N; i++) {
            p[i] = sc.nextInt();
            if (p[i] != i) {
                cnt++;
            }
        }
        if (cnt < 3) {
            System.out.println("YES");
        } else {
            System.out.println("NO");
        }
    }
} public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int[] p = new int[N + 1];
        int cnt = 0;
        for (int i = 1; i <= N; i++) {
            p[i] = sc.nextInt();
            if (p[i] != i) {
                cnt++;
            }
        }
        if (cnt < 3) {
            System.out.println("YES");
        } else {
            System.out.println("NO");
        }
    }
} Main
import java.util.Scanner;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int[] p = new int[N + 1];
        int cnt = 0;
        for (int i = 1; i <= N; i++) {
            p[i] = sc.nextInt();
            if (p[i] != i) {
                cnt++;
            }
        }
        if (cnt < 3) {
            System.out.println("YES");
        } else {
            System.out.println("NO");
        }
    }
}
