#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 cnt=0;
	for (auto itr = m.begin(); itr != m.end(); itr++) {
		if(itr->second == 1) cnt++;
	}
	cout << cnt << endl;
}