#include <iostream>
#include <algorithm>
#include <vector>

void solve() {
    int n;
    std::cin >> n;

    std::vector<int> xs(n);
    for (auto& x : xs) std::cin >> x;
    std::reverse(xs.begin(), xs.end());

    int nxt = n;
    for (auto x : xs) {
        if (x == nxt) --nxt;
    }

    std::cout << nxt << std::endl;
}

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

    solve();

    return 0;
}