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

int main() {
  int n, t, ans = 0;
  cin >> n;
  map<int, int> mp;
  for (int i = 0; i < n; i++) {
    cin >> t;
    mp[t]++;
  }
  for (auto itr = mp.begin(); itr != mp.end(); itr++) {
    if (itr->second == 1) ans++;
  }
  cout << ans << endl;
}