#include <bits/stdc++.h>
using namespace std;
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    unsigned long long n;
    unordered_map<unsigned long long,unsigned long long> h;
    cin >> n;
    while(cin >> n)
        ++h[n];
    n=0;
    for(auto&& e : h)
        n += (e.second==1);
    cout << n << endl;
}