#include <bits/stdc++.h>

using namespace std;

int main()
{
    int n; cin >> n;
    vector<int>a(n+1);
    for(int i = 1; i <= n; i++)
    {
        int x; cin >> x;
        a[x] = i;
    }
    int maxi = 0;
    int index = 0;
    int maxinverzio = 0;
    int c = -1, b;
    for(int i = 1; i <= n; i++)
    {
       if(i > 1)
       {
          if(maxi - a[i] > maxinverzio)
          {
              maxinverzio = maxi - a[i];
              c = a[i], b = maxi;
          }
       }
       maxi = max(maxi, a[i]);
    }
    if(c == -1)
    {
        cout << -1;
        return 0;
    }
    cout << c << " " << b;
    return 0;
}