#include<bits/stdc++.h>
using namespace std;
using Int = long long;
//INSERT ABOVE HERE
signed main(){
  Int n;
  cin>>n;
  map<Int, Int> m;
  for(Int i=0;i<n;i++){
    Int a;
    cin>>a;
    m[a]++;
  }
  Int ans=0;
  for(auto p:m) ans+=p.second==1;
  cout<<ans<<endl;
  return 0;
}