#define _USE_MATH_DEFINES
#include<iostream>
#include<vector>
#include<algorithm>
#include<cmath>
#include<string>
#include<iomanip>
#include<numeric>
#include<queue>
#include<deque>
#include<stack>
#include<set>
#include<map>
#include<random>
using namespace std;
typedef long long ll;
const int mod=998244353;
int main(){
	int n,a;
	cin>>n;
	map<int,int>mp;
	while(cin>>a)
		mp[a]++;
	int ans=0;
	for(auto x:mp)
		if(x.second==1)
			ans++;
	cout<<ans<<endl;
}