#include <bits/stdc++.h>
using namespace std;
const int maxA = 6e2 + 6;
int n, ans, a;
bool Arr[maxA];
int main() {
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> a;
    if (!Arr[a] && a) ans++;
    Arr[a] = 1;
  }
  cout << ans;
  return 0;
}
