#include <bits/stdc++.h>
using namespace std;
set<int> scor;
int main() {
  int n, a;
  cin >> n;
  for (int i = 1; i <= n; i++) {
    cin >> a;
    if (a != 0) {
      scor.insert(a);
    }
  }
  cout << scor.size();
  return 0;
}
