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 PYTHON3):

Solution:
def res():
    n = int(input())
    v = [int(i) for i in input().split()]
    
    ans = sorted(v)
    
    if(v == ans):
        return "0 0"

    try:
        ini = 0
        temp = []
        
        while v[ini] < v[ini+1]:
            temp.append(v[ini])
            ini += 1
        
        fim = ini
        v2 = []
        while fim < n-1 and v[fim] > v[fim+1]:
            v2.append(v[fim])
            fim += 1
        v2.append(v[fim])
        
        ini += 1
        fim += 1
        
        temp += v2[::-1] + v[fim:]
        
        if temp == ans:
            return str(ini) + ' ' + str(fim)
        else:
            return "0 0"
        
    except:
        return "0 0"
        
def main():
    print(res())

main()