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

#include <iostream>
#include <deque>
#include <algorithm>
#include<climits>

using namespace std;

struct adat
{
    int szam, hely;
};
bool hasonlit(adat a, adat b)
{
    if (a.szam > b.szam) return 1;
    else return 0;
}
deque<adat>x;
int  i, n, j, k,kezd,veg;
adat mini, maxi;

int main()
{
    cin >> n;
    x.resize(n + 1);
    for (i = 1; i <= n; ++i)
    {
        cin >> x[i].szam;
        x[i].hely = i;
    }
    sort(x.begin(), x.end(), hasonlit);
    mini.szam = x[1].hely;
    for (i = 2; i <= n; ++i)
    {
        if (x[i].hely < mini.szam) mini.szam = x[i].hely;
        else if (x[i].hely - mini.szam > veg-kezd)
        {
            kezd = mini.szam;
            veg = x[i].hely;
        }
    }
    if (!(veg - kezd)) cout << -1;
    else cout << kezd << " " << veg;
    return 0;
}
/*
5
4 3 5 1 2


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

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