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 PYTHON):

Solution:
'''
Created on Oct 21, 2011

@author: herman
'''
from string import split
import sys

N = int(sys.stdin.readline())

vals = [int(x) for x in split(sys.stdin.readline())]

low = N
high = -1

for i in xrange(N):
    if vals[i] != i + 1:
        if i < low:
            low = i
        if i > high:
            high = i
            
#print (low,high, vals[low:(high+1)])
if high != -1:
    newseg = vals[low:(high+1)]
    newseg.reverse()
    lowseg = []
    if low > 0:
        lowseg = vals[0:low]
    highseg = []
    if high < N-1:
        highseg = vals[(high+1):]
    #print (lowseg,newseg,highseg)
    if lowseg + newseg + highseg == [x for x in xrange(1,N+1)]:
        print "%d %d" % (low+1,high+1)
    else:
        print "0 0"
else:
    print "0 0"