#include<bits/stdc++.h>
using namespace std;
int main(){
    int n,ans=0;
    cin>>n;
    map<int,int> m;
    for(int i=0;i<n;++i){
        int a;
        cin>>a;
        if(m.count(a)==0)m.emplace(a,1);
        else ++m[a];
    }
    for(auto x:m)if(x.second==1)++ans;
    cout<<ans<<endl;
}