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