#include<iostream>
#include<vector>

int main() {
	int n;
	std::cin >> n;

	std::vector<int> v(n);
	for (int i = 0; i < n; i++) {
		std::cin >> v[i];
	}

	int count = 0;
	for (int i = n - 1; i >= 0; i--) {
		if (v[i] == n) {
			count++;
			n--;
		}
	}

	std::cout << v.size() - count << std::endl;
	return 0;
}