#define _GLIBCXX_DEBUG
#define ll long long
#include <bits/stdc++.h>
using namespace std;
using Graph = vector<vector<int>>;

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