#include <bits/stdc++.h>
using namespace std;
int n, x, td[601], ans;
int main() {
  cin >> n;
  for (int i = 1; i <= n; i++) {
    cin >> x;
    if (x != 0 && td[x] == 0) {
      ++ans;
      td[x]++;
    }
  }
  cout << ans;
}
