#include<iostream>
#include<map>

using namespace std;

int main(){
	int n, input;
	cin >> n;
	map<int, int> mp;
	for(int i=0; i<n; ++i){
		cin >> input;
		++mp[input];
	}

	int ans = 0;
	for(auto it = mp.begin(); it != mp.end(); ++it){
		ans += (it->second == 1);
	}
	cout << ans << endl;
}