#include<iostream>
#include<map>
using namespace std;
int main(){
	int n; cin >> n;
	map<int, int> m;
	for (int i = 0; i < n; i++){
		int a; cin >> a;
		m[a]++;
	}
	int a = 0;
	for (auto i: m){
		a += i.second == 1;
	}
	cout << a << endl;
	return 0;
}