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:
n=int(input())
l=[int(i) for i in input().split()]
f=0
if l==sorted(l):
    print('0 0')
    exit()
if len(set(l))!=n:
    print('0 0')
    exit()
f=0
for i in range(0,n):
    if l[i]!=(i+1):
        f=1 
        indx=l.index(i+1)
        curr=i 
        arr=l[i:indx+1]
        arr=arr[::-1]
        def check(arr):
            n=len(arr)
           # print(arr)
            for i in range(1,n):
                if arr[i]!=arr[i-1]+1:
                    return 0
            return 1
        if check(arr) and l[indx+1:]==sorted(l[indx+1:]):
            print(curr+1,indx+1)
        else:
            print('0 0')
        exit()
print('0 0')