#include <iostream>
#include <map>
using namespace std;

int main()
{
	int N, i, t, ans = 0;
	cin >> N;

	map<int, int> A;
	for (i = 0; i < N; i++)
		cin >> t, A[t]++;

	for (auto itr = A.begin(); itr != A.end(); itr++)
		if (itr->second == 1) ans++;

	cout << ans << endl;
	
	return 0;
}