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

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

	int n;
    int a[100001];

    cin >> n;

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

    int maxI = -100001;
    int maxDiff = 0;
    int x, y;

    for (int i = 0; i < n - 1; i++) {
        if (a[i] > maxI) {
            maxI = a[i];

            int j = n - 1;
            while (j > i && a[i] <= a[j]) {
                j--;
            }
            if (j - i > maxDiff) {
                maxDiff = j - i;
                x = i + 1;
                y = j + 1;
            }
        }
    }

    if (maxDiff) {
        cout << x << " " << y;
    }
    else {
        cout << "-1";
    }
}