#include<bits/stdc++.h>
using namespace std;
int main() {
	int N;
	cin >> N;
	vector<int> a(N);
	for (auto& it : a)cin >> it;
	reverse(a.begin(), a.end());
	for (auto& it : a)N-=(it==N);
	cout << N << endl;
	return 0;
}