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.IOException; 
import java.io.InputStreamReader; 
import java.util.StringTokenizer; 
import java.util.*;
 
public class Main 
{ 
    public static void ans(int []arr,int n){
        int l=0,r=0;
        for(int i=0;i<n-1;i++){
            if(arr[i]>arr[i+1]){
                l=i;
                break;
            }
        }
        for(int i=l;i<n;i++){
            if(i<n-1 && arr[i]<arr[i+1]){
                r=i;
                break;
            }else if(i==n-1){
                r=i;
                break;
            }
        }
        if(l==0 && r==0){
            System.out.println("0 0");
            return;
        }
    //   System.out.print(l+" "+r);
   int ll=l,rr=r;
        while(l<r)
        { 
            int tempswap = arr[l];  
                arr[l] = arr[r];  
                arr[r] = tempswap;  
                l++;r--;
        }  
        for(int i=0;i<n-1;i++){
           if(arr[i]>arr[i+1])
           {
               System.out.println("0 0");
            return;
           }
        }
        System.out.println((ll+1)+" "+(rr+1));
            return;
    }
    public static void main(String[] args) throws IOException 
    { 
  
       BufferedReader br = new BufferedReader( 
                              new InputStreamReader(System.in));
        int n=Integer.parseInt(br.readLine());
        int arr[]=new int[n];
         StringTokenizer st =new StringTokenizer(br.readLine()); 
        for(int i=0;i<n;i++){
            arr[i]=Integer.parseInt(st.nextToken());
        }
        ans(arr,n);
}}