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 Main 
{
    public static void main(String[] args)
    {
        Scanner sc=new Scanner(System.in);
        int t=sc.nextInt();
        boolean boo=true;
        int count=0,l=0,r=0;
        int[] org =new int[t];
        for(int i=0;i<t;i++)
        {
            org[i]=i+1;
        }
        int[] given=new int[t];
        for(int i=0;i<t;i++)
        {
            given[i]=sc.nextInt();
            if(given[i]!=org[i])
            {
                count++;
                boo=false;
                if(count==1)
                {
                    l=i;
                }
                else
                {
                   r=i; 
                }
            }
            //System.out.println(l+" "+r);
        }
          int start=l,end=r;
                   while (l < r) 
                   { 
                      int temp = org[l];  
                       org[l] = org[r]; 
                        org[r] = temp; 
                         l++; 
                          r--; 
                    }  
       for(int i=0;i<t;i++)
       {
           if(org[i]!=given[i])
           {
              System.out.println("0 0");
              return;
           }
           
       }
       if(boo==false)
       System.out.println((start+1 )+" "+ (end+1));
       else
       System.out.println(start+" "+ (end));
    }
}