#include <bits/stdc++.h>
using namespace std;

int main() {
	int N;
	cin >> N;
	vector<int> A(N);
    long long c;
	map<int, int> m;
	for (int i = 0; i < N; i++) {
		cin >> c;
		m[c]++;
	}
	int ans = 0;
	for (auto it : m) {
		if (it.second == 1)
			ans++;
	}
	cout << ans << endl;
}