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


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