#include <iostream>
#include <map>
using namespace std;

int main() {
	int n, a, cnt = 0;
	map<int, int> table;
	
	cin >> n;
	for(int i=0;i<n;++i){
		cin >> a;
		if(table.find(a) == table.end()){
			table[a] = 1;
		}else{
			++table[a];
		}
	}
	
	for(map<int, int>::iterator it=table.begin();it!=table.end();++it){
		if((*it).second == 1)++cnt;
	}
	cout << cnt << endl;
	
	return 0;
}