#include <bits/stdc++.h>
using namespace std;
int main(int argc, char const *argv[]) {
  int n;
  cin >> n;
  int a[n];
  int count[601];
  for (int i = 0; i < 601; i++) count[i] = 0;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    count[a[i]]++;
  }
  int ans = 0;
  for (int i = 1; i < 601; i++) {
    if (count[i] != 0) ans++;
  }
  cout << ans << endl;
}
