#include <bits/stdc++.h>
using namespace std;
int n;
int a[605];
int b[605];
int c;
int main() {
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    if (b[a[i]] == 0 && a[i] != 0) {
      c++;
      b[a[i]] = 1;
    }
  }
  cout << c << endl;
  return 0;
}
