#include <bits/stdc++.h>

using namespace std;

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

    map<int, int> mp;
    for (int i = 0; i < n; ++i) {
        int t;
        cin >> t;
        mp[t]++;
    }

    int ans = 0;
    for (auto x:mp) {
        if (x.second == 1) ans++;
    }
    cout << ans << endl;
    return 0;
}