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