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.
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.
def main():
    num = int(input())
    data = [int(x) for x in input().split()]
    left = 0
    right = 0
    sign = True
    i = 0
    j = 0
    
    #find left
    for i in range(len(data)):
        if data[i] != i+1:
            break
    left = i+1
    
    #check left
    if left>num:
        sign = False
        
    #find right
    for j in range(i+1, num):
        if data[j] - data[j-1] != -1:
            break
    right = j
    
    #check right
    if right<1:
        sign = False
        
    #check data after right
    for i in range(j, num):
        if data[i] != i+1:
            sign = False
            break
   
    if sign:
        print(left,right)
    else:
        print("0 0\n")

main()

    
        

    
