#include <iostream>
#include <vector>
using namespace std;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int n;
    cin >> n;
    vector<int> a(n);
    for (int i = 0; i < n; ++i)
        cin >> a[i];

    int best_i = -1, best_j = -1;
    // Most: minden i-re megnézzük a lehető legtávolabbi j-t, ahol a[i] > a[j]
    int max_dist = -1;
    for (int i = 0; i < n - 1; ++i) {
        for (int j = n - 1; j > i; --j) {
            if (a[i] > a[j]) {
                if (j - i > max_dist) {
                    max_dist = j - i;
                    best_i = i;
                    best_j = j;
                }
                // Mivel j csökken, innen csak rövidebb távokat kapnánk → break
                break;
            }
        }
    }

    if (best_i == -1) {
        cout << -1 << '\n';
    } else {
        cout << best_i+1<< " " << best_j+1<< '\n';
    }

    return 0;
}