// inverzio.cpp : This file contains the 'main' function. Program execution begins and ends there.
//

#include <iostream>
#include <queue>
#include <algorithm>

#define ll long long
using namespace std;

ll n;

int main()
{
    cin >> n;
    vector<pair<ll,ll>>x(n);
    for (int i = 0; i < n; ++i)
    {
        cin >> x[i].first;
        x[i].second = i + 1;
    }
    sort(x.begin(), x.end(), [](pair<ll,ll> a, pair<ll,ll> b)
        {
            return a.first > b.first;
        });
    ll mini = x[0].second,v=0,k=0;
    for (int i = 1; i < n; ++i)
    {
        mini = min(x[i].second, mini);
        if(x[i].second - mini > v - k)
        {
            v = x[i].second;
            k = mini;
        }
    }
    if (k == v)cout << "-1";
    else cout << k << " " << v;
    return 0;
}

// Run program: Ctrl + F5 or Debug > Start Without Debugging menu
// Debug program: F5 or Debug > Start Debugging menu

// Tips for Getting Started: 
//   1. Use the Solution Explorer window to add/manage files
//   2. Use the Team Explorer window to connect to source control
//   3. Use the Output window to see build output and other messages
//   4. Use the Error List window to view errors
//   5. Go to Project > Add New Item to create new code files, or Project > Add Existing Item to add existing code files to the project
//   6. In the future, to open this project again, go to File > Open > Project and select the .sln file