#include <iostream>
#include <vector>
#include <map>
using namespace std;
int main(void) {
	int n, a;
	cin >> n;
	map<int, int> mp;
	for (int i = 0; i < n; ++i) {
		cin >> a;
		++mp[a];
	}
	int ans = 0;
	for (auto x : mp) {
		if (mp[x.first] == 1) ++ans;
	}
	cout << ans << endl;
	return 0;
}