#include <bits/stdc++.h>
using namespace std;
bool car[601];
short n;
int main() {
  cin >> n;
  short v[n];
  for (short i = 0; i < n; ++i) {
    cin >> v[i];
    car[v[i]] = 1;
  }
  short count = 0;
  for (short i = 1; i <= 600; ++i)
    if (car[i]) ++count;
  cout << count;
  return 0;
}
