#include <bits/stdc++.h>
using namespace std;
bool vis[602];
int main() {
  int n, ans = 0;
  cin >> n;
  int a[n];
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    if (!vis[a[i]]) vis[a[i]] = 1;
  }
  for (int i = 1; i <= 600; i++) {
    if (vis[i]) ans++;
  }
  cout << ans << endl;
  return 0;
}
