#include <bits/stdc++.h>
using namespace std;

int main() {
  int n;
  cin >> n;
  vector<int> szam(n);
  vector<int> maxi(n, -100001);
  vector<int> mini(n, 100001);
  cin >> szam[0];
  maxi[0] = szam[0];
  for(int i = 1; i < n; i++){
    cin >> szam[i];
    maxi[i] = max(szam[i], maxi[i - 1]);
  }
  mini[n - 1] = szam[n - 1];
  for(int i = n - 2; i >= 0; i--){
    mini[i] = min(szam[i], mini[i + 1]);
  }
  int bal = 0, jobb = 1;
  int maxdis = 0, maxb = -1, maxj = 0;
  while(bal < n){
    while(jobb < n && mini[jobb] <= maxi[bal]){
      jobb++;
    }
    if(jobb == n && mini[jobb - 1] >= maxi[bal]){
      bal++;
      continue;
    }
    if(maxdis < jobb - bal && mini[jobb - 1] < maxi[bal]){
      maxdis = jobb - bal;
      maxb = bal;
      maxj = jobb - 1;
    }
    bal++;
  }
  if(maxb == -1 || maxb == maxj) cout << -1;
  else cout << maxb + 1 << " " << maxj + 1;
}