#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <climits>
#include <cfloat>
#include <map>
#include <utility>
#include <ctime>
#include <set>
#include <iostream>
#include <memory>
#include <string>
#include <unordered_set>
#include <cstring>
#include <vector>
#include <algorithm>
#include <functional>
#include <fstream>
#include <sstream>
#include <complex>
#include <bitset>
#include <stack>
#include <queue>
#include <cstring>
#include <numeric>
#include <cassert>
using namespace std;
#define rep(i,n) for(int (i)=0;(i)<(n);(i)++)
#define rev(i,n) for(int i=(n)-1;(i)>=0;(i)--)
#define all(a) (a).begin(),(a).end()
#define pb(a) push_back(a)
#define bitcount(b) __builtin_popcount(b)
template<typename T, typename S> vector<T>& operator<<(vector<T>& a, S b) { a.push_back(b); return a; }
template<typename T> void operator>>(vector<T>& a, int b) {while(b--)if(!a.empty())a.pop_back();}
bool isprime(int n){ if(n<2)return false;  for(int i=2;i*i<=n;i++)if(n%i==0)return false;  return true;} 

int main(){
	map<int,int> v;
	int n;
	cin >> n;
	for(int i = 0 ; i < n ; i++){
		int t;
		cin >> t;
		v[t]++;
	}
	int ans = 0;
	for( auto i : v ){
		if( i.second == 1 ) ans++;
	}
	cout << ans << endl;
}