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 MyClass {
   /* public static int gcd(int k,int p)
    {
        if (p == 0)
        return k;
    return gcd(p, k %p);
    }*/
    public static void main(String args[]) {
     Scanner sc=new Scanner(System.in);
    // int t=sc.nextInt();
   //  while(t-->0)
     //{  
         int n=sc.nextInt();
         int l=0,r=0;
         int[] arr=new int[n+1];
         for(int i=1;i<n+1;i++)
         {  
             arr[i]=sc.nextInt();
             if(arr[i]!=i&&l==0)
             {
                 l=i;
                 r=arr[i];
             }
             
         }
        int j=l,h=r;
        while(j<=h)
        {
            int temp=arr[j];
            arr[j]=arr[h];
            arr[h]=temp;
            j++;
            h--;
        }
         for(int i=1;i<n+1;i++)
         {
             if(arr[i]!=i)
             {
                 l=0;
                 r=0;
                 break;
             }
         }
         System.out.println(l+" "+r);
         

//}
}
}