#include<bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(int i=a;i<b;i++)



int main()
{
	int N;
	cin >> N;

	map<int, int> cnt;
	rep(i, 0, N) {
		int A;
		cin >> A;
		cnt[A]++;
	}

	int ans = 0;
	for (auto p : cnt) if (p.second == 1) ans++;
	cout << ans << endl;
}