#include <iostream>
#include <cstdio>
#include <map>
using namespace std;
#define rep(i,n) for(int i=0;i<(n);i++)

int main(void){
	int n; cin >> n;
	map<int, int> m;
	rep(i, n){
		int tmp; cin >> tmp;
		m[tmp]++;
	}
	int ans = 0;
	for(auto x : m){
		if(x.second == 1) ans++;
	}
	printf("%d\n", ans);
	return 0;
}