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.util.*;
public class spolitperm{
     public static void main(String[] args) {
        Scanner br = new Scanner(System.in);
        int n = br.nextInt();
        int[] nums = new int[n];
        int start = 0;
        int end = 0;
        for(int i = 0;i<n;i++){
        	nums[i] = br.nextInt();
        }
        for(int i = 0;i<n;i++){
        	if(nums[i] == i+1){

        	}
        	else{
        		if(nums[nums[i]-1] == i+1){
        			start = i+1;
        			end = nums[i];
        			for(int j = start-1;j<end-1;j++){
        				if(nums[i] == nums[i+1]+1){

        				}
        				else{
        					start = 0;
        					end = 0;
        					break;
        				}
        			}
        			for(int j = end;j<n;j++){
        				if(nums[j] != j+1){
        					start = 0;
        					end = 0;
        					break;
        				}
        			}
        		}
        		break;
        	}
        }
        System.out.println(start + " " + end);
     }
}