#include <bits/stdc++.h>

using namespace std;

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

    map<int, int> m;

    for (int i = 0; i < N; ++i) {
        int a; cin >> a;
        m[a]++;
    }

    int cnt = 0;

    for (auto &item : m) if (item.second == 1) cnt++;

    cout << cnt << endl;
}