#include<iostream>
#include<map>

using namespace std;

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