#include <bits/stdc++.h>
using namespace std;

int main() {
    int N; cin >> N;
    unordered_map<int, int> m;
    for (int i = 0; i < N; i++) {
        int A; cin >> A;
        m[A]++;
    }
    int c = count_if(m.begin(), m.end(), [](const pair<int,int>& p) {
        return p.second==1;
    });
    cout << c << endl;
}