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