#include <iostream>
#include <stack>
#include <set>

using namespace std;

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

	int N;
	cin >> N;
	stack<int> yearS;
	for (int i = 0; i < N; i++) {
		int year;
		cin >> year;
		yearS.push(year);
	}
	set<int> countedS;
	int minimum;
	for (int i = N; i > 0; i--) {
		if (countedS.count(yearS.top()) == 0) {
			countedS.insert(yearS.top());
			minimum = i;
		}
		yearS.pop();
	}
	cout << minimum << '\n';
}