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

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