#include <bits/stdc++.h>
using namespace std;

int main()
{
	int N;
	cin >> N;
	map<long long, int> mp;
	for( int i = 0; i < N; i++ ) {
		long long A;
		cin >> A;
		mp[A]++;
	}
	int ans = 0;
	for( auto it = mp.begin(); it != mp.end(); it++ ) {
		if( it->second == 1 ) ans++;
	}

	cout << ans << endl;
}