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>
const double EPS = 1e-9;
const int MOD = 1000003;
const int INF = 2000 * 1000 * 1000;
const int MAX = 4000000;
using namespace std;
int popcount(int n) {
  bitset<32> b(n);
  return b.count();
}
long long gcd(long long a, long long b) { return b == 0 ? a : gcd(b, a % b); }
int lcm(int a, int b) {
  int temp = gcd(a, b);
  return temp ? (a / temp * b) : 0;
}
template <typename T>
T modpow(T base, T exp, T modulus) {
  base %= modulus;
  T result = 1;
  while (exp > 0) {
    if (exp & 1) result = (result * base) % modulus;
    base = (base * base) % modulus;
    exp >>= 1;
  }
  return result;
}
inline bool isInteger(const std::string& s) {
  if (s.empty() || ((!isdigit(s[0])) && (s[0] != '-') && (s[0] != '+')))
    return false;
  char* p;
  strtol(s.c_str(), &p, 10);
  return (*p == 0);
}
int arr[1005], tmp[1005];
int main() {
  int n;
  cin >> n;
  for (int i = 0; i < n; i++) cin >> arr[i];
  for (int i = 0; i < n; i++) {
    for (int j = i + 2; j <= n; j++) {
      for (int k = 0; k < n; k++) tmp[k] = arr[k];
      reverse(tmp + i, tmp + j);
      bool f = 1;
      for (int k = 0; k < n; k++)
        if (tmp[k] != k + 1) {
          f = 0;
          break;
        }
      if (f) {
        cout << i + 1 << " " << j << endl;
        return 0;
      }
    }
  }
  cout << "0 0" << endl;
  return 0;
}