#include <bits/stdc++.h>

using namespace std;

int main()
{
    ios::sync_with_stdio(false);
    int n;
    cin >> n;
    vector<int> s(n + 1), pos(n + 1);
    for (int i = 1; i <= n; i++) {
        cin >> s[i];
        pos[s[i]] = i;
    }

    int maxpos = 0, maxdist = 0, maxi = -1, maxj = -1;
    for (int i = 1; i <= n; i++) {
        if (maxpos - pos[i] > maxdist) {
            maxdist = maxpos - pos[i];
            maxi = pos[i];
            maxj = maxpos;
        }
        maxpos = max(maxpos, pos[i]);
    }
    if (maxdist > 0) cout << maxi << " " << maxj << "\n";
    else cout << "-1\n";
    return 0;
}
/*
5
4 3 5 1 2
*/