Function main

CSES_Problems/Distinct_Numbers/solution.cpp:10–21

*/

signed main() {
        int n;
        cin >> n;
        set<int> s;
        for(int i = 0; i < n; i++) {
                int x;
                cin >> x;
                s.insert(x);
        }
        cout << (int)s.size() <<"\n";
        return 0;
}