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 CPP):

Solution:
#include <bits/stdc++.h>
using namespace std;
bool SortbySecDesc(const pair<long long, long long> &a,
                   const pair<long long, long long> &b) {
  return a.second > b.second;
}
bool sortinrev(const pair<int, int> &a, const pair<int, int> &b) {
  return (a.first > b.first);
}
int String_to_int(string s) {
  stringstream geek(s);
  int ans = 0;
  geek >> ans;
  return ans;
}
int S_I(string s) { return stoi(s); }
vector<long long> v, v1, v2;
int main() {
  long long n;
  cin >> n;
  for (int i = 0; i < n; i++) {
    long long x;
    cin >> x;
    v.push_back(x);
  }
  v1 = v;
  sort(v1.begin(), v1.end());
  if (v == v1) {
    cout << 0 << " " << 0 << "\n";
    ;
    return 0;
  }
  int pos = INT_MIN, pos1 = INT_MAX;
  for (int i = 0; i < n; i++) {
    if (v[i] != v1[i]) {
      pos = max(pos, i);
      pos1 = min(pos1, i);
    }
  }
  reverse(v.begin() + pos1, v.begin() + pos + 1);
  if (v == v1) {
    cout << pos1 + 1 << " " << pos + 1 << "\n";
    ;
  } else {
    cout << 0 << " " << 0 << "\n";
    ;
  }
  return 0;
}