#include <iostream>
using namespace std;

int main() {
    int N;
    cin >> N;

    int p[100000];
    int i = 0;
    while (i < N) {
        cin >> p[i];
        i++;
    }

    int maxcs = 0;
    int legcsal = -1;
    i = 0;
    while (i < N) {
        int cs = 0;
        int j = i + 1;
        while (j < N && p[j] <= p[i])
            j++;
        if (j < N)
            cs = j - i;
        if (cs > maxcs) {
            maxcs = cs;
            legcsal = i;
            i = j;
        }
        else {
            break;
        }
    }

    if (legcsal == -1)
        cout << -1;
    else
        cout << legcsal + 1;
    cout << endl;
    return 0;
}