#include <iostream>
#include <vector>

using namespace std;

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

    for (int i = 0; i < n; i++)
    {
        bool later = false;
        int val = years[i];
        for (int j = i + 1; j < n; j++)
        {
            if (years[j] == val)
            {
                later = true;
                break;
            }
        }
        if (!later)
        {
            cout << i + 1;
            break;
        }
    }
}