#include <iostream>
#include <map>

using namespace std;

int main() {
    int N;
    cin >> N;

    map<int, int> map;
    for (int i = 0; i < N; i++) {
        int A;
        cin >> A;
        map[A]++;
    }

    int ans = 0;
    for (auto p: map) {
        if (p.second == 1) ans++;
    }

    cout << ans << endl;
}