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

#define int long long
#define pb emplace_back
#define sz(v) (int)(v.size())
#define all(v) (v.begin(),v.end())
signed main(){
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	// freopen("input.txt","r",stdin);
	// freopen("output.txt","w",stdout);
	int n;
	cin >> n;
	vector<int> v(n);
	unordered_map<int,int> arr;
	for(int i = 0;i<n;i++){
		cin >> v[i];
		arr[v[i]]++;

	}
	int ans = 0;
	for(int i = 0;i<n;i++){
		if(arr[v[i]] == 1)
			ans++;
	}
	cout << ans << " ";
	return 0;
}