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

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

    int ans = 0;
    for (auto& p : mp)
        if (p.second == 1)
            ans++;

    cout << ans << endl;
}