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

int main(void) {
	int N;
	cin >> N;
	vector<int> A(N);
	for(int i = 0; i < N; ++i) cin >> A[i];
	
	unordered_map<int, int> m;
	for(int i = 0; i < N; ++i) m[A[i]] += 1;
	
	int ans = 0;
	for(auto [_, amo] : m) if(amo == 1) ans += 1;
	cout << ans << "\n";
	return 0;
}