#include <iostream>
#include <map>
using namespace std;
int main() {
	int n, k, j = 0;
	map<int, int> mp;
	cin >> n;
	for(int i = 0; i < n; i++)
		cin >> k, mp[k]++;
	for(auto m = mp.begin(); m != mp.end(); m++)
		if(m->second == 1) j++;
	cout << j << endl;
}