#include <bits/stdc++.h>
using namespace std;
int gcd(int a, int b) {
  if (b > a) return gcd(b, a);
  return b == 0 ? a : gcd(b, a % b);
}
void swap(int *m, int *n) {
  int temp = *n;
  *n = *m;
  *m = temp;
}
struct sort_pred {
  bool operator()(const std::pair<int, int> &left,
                  const std::pair<int, int> &right) {
    return left.first < right.first;
  }
};
int compare(const void *a, const void *b) {
  const int *ia = (const int *)a;
  const int *ib = (const int *)b;
  return *ia - *ib;
}
int a[1000];
int b[1000];
int main() {
  int n;
  scanf("%d", &n);
  int i, j;
  int k = 0;
  int prev = -1;
  int uniflag = 0;
  int begin = -1, end = -1, flag = 0, flag1 = 0;
  for (i = 0; i < n; i++) {
    scanf("%d", &a[i]);
    if (a[i] != i + 1 && flag == 0) {
      begin = i + 1;
      flag = 1;
      b[k++] = a[i];
      prev = a[i];
    } else if (a[i] == prev - 1) {
      end = i + 1;
      b[k++] = a[i];
      prev = a[i];
    } else if (prev != -1 && a[i] != i + 1) {
      uniflag = 1;
    }
  }
  int len = end - begin + 1;
  sort(b, b + len);
  int count1 = 0;
  for (i = 0; i < len; i++) {
    if (b[i] == begin + i) count1++;
  }
  if (uniflag == 1)
    cout << "0 0" << endl;
  else if (count1 == len)
    cout << begin << " " << end << endl;
  else
    cout << "0 0" << endl;
  return 0;
}
