Problem: Vasya collects coins: he has exactly one coin for every year from 1 to n. Naturally, Vasya keeps all the coins in his collection in the order in which they were released. Once Vasya's younger brother made a change — he took all the coins whose release year dated from l to r inclusively and put them in the reverse order. That is, he took a certain segment [l, r] and reversed it. At that the segment's endpoints did not coincide. For example, if n = 8, then initially Vasya's coins were kept in the order 1 2 3 4 5 6 7 8. If Vasya's younger brother chose the segment [2, 6], then after the reversal the coin order will change to 1 6 5 4 3 2 7 8. Vasya suspects that someone else could have spoilt the permutation after his brother. Help him to find that out. Check if the given permutation can be obtained from the permutation 1 2 ... n using exactly one segment reversal. If it is possible, find the segment itself.

Input

The first line contains an integer n (1 ≤ n ≤ 1000) which is the number of coins in Vasya's collection. The second line contains space-separated n integers which are the spoilt sequence of coins. It is guaranteed that the given sequence is a permutation, i.e. it contains only integers from 1 to n, and every number is used exactly 1 time.

Output

If it is impossible to obtain the given permutation from the original one in exactly one action, print 0 0. Otherwise, print two numbers l r (1 ≤ l < r ≤ n) which are the endpoints of the segment that needs to be reversed to obtain from permutation 1 2 ... n the given one.

Examples

Input

8
1 6 5 4 3 2 7 8


Output

2 6


Input

4
2 3 4 1


Output

0 0


Input

4
1 2 3 4


Output

0 0

Solution (in JAVA):

Solution:
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.Map;

public class B {
    private static boolean isOK(int[] arr2, int start, int end){
        boolean result = true;
        int[] arr = Arrays.copyOf(arr2, arr2.length);
        while (start < end){
            int t = arr[start];
            arr[start]=arr[end];
            arr[end] = t;
            start++;
            end--;

        }
        for (int i=0;i<arr.length;i++){
            if (arr[i]!=i+1){
                return false;
            }
        }
        return true;

    }

    public static void main(String[] args) {


        try {

            BufferedReader in = System.getenv("com.apple.java.jvmMode") != null ? new BufferedReader(new FileReader("input.txt")) :
                    new BufferedReader(new InputStreamReader(System.in));


            int num = Integer.parseInt(in.readLine());
            int[] nums = new int[num];

            int res = 0;
            String s = in.readLine();
            String[] arr = s.split(" ");
            for (int i = 0; i < num; i++) {
                nums[i] = Integer.parseInt(arr[i]);
            }
            boolean found = false;
            for (int i=0;i<num-1;i++){
                for (int j=i+1;j<num;j++){
                    if (isOK(nums, i, j)){
                        found = true;
                        System.out.println((i+1)+" "+(j+1));
                        break;
                    }
                }
            }
            if (!found){
                System.out.println("0 0");
            }

            in.close();
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }
}