#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm> 
#include <map>
#include <vector> 

using namespace std;

int main(){
	int n;scanf("%d",&n);
	int ans=0;map<int,int> cnt;
	int num;
	for(int i=0;i<n;i++){scanf("%d",&num);cnt[num]++;}
	for(auto it=cnt.begin();it!=cnt.end();it++)if(it->second==1)ans++;
	printf("%d\n",ans);
	
	
	
	
	return 0;
}