#pragma GCC optimize("Ofast")
#include<iostream>
#include<stdio.h>
#include<algorithm>
#include<vector>
#include<string.h>
#include<math.h>
#include<map>
#include<iomanip>
#include<queue>

const long long INFL = 1e17+7;
const long long INFI = 1e9+7;
const long long MOD = 1e9+7;
const double EXP = 1e-8;
const double PI=acos(-1);

using namespace std;

int main(){
	cin.tie(0);
	ios::sync_with_stdio(false);
	
	int n;
	cin >> n;
	map<int,int> mp;
	for(int i=0;i<n;i++){
		int x;
		cin >> x;
		mp[x]++;
	}
	int cnt=0;
	for(auto itr=mp.begin();itr!=mp.end();itr++){
		if(itr->second == 1)cnt++;
	}
	cout << cnt << endl;
	return 0;
}