frequencia.cpp

//solucao de davi gabriel (modificada)

#include <bits/stdc++.h>

using namespace std;

int main() {

    int n, al, ans = 0;

    cin >> n;
  
    set<int> mark;
  
    for(int i = 0; i < n; i++){

        cin >> al;
        
        mark.insert(al);
    }

    cout << mark.size() << "\n";

    return 0;
}