#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, k;
  int a[700] = {0};
  cin >> n;
  while (n--) {
    cin >> k;
    a[k] = 1;
  }
  int res = 0;
  for (int i = 1; i <= 600; i++) {
    if (a[i] == 1) res++;
  }
  cout << res << endl;
}
