#include <bits/stdc++.h>
using namespace std;
const int N = 1e6 + 5;
int n, a[N], b[N], ans;
int main() {
  scanf("%d", &n);
  for (register int i = 1; i <= n; i++) {
    scanf("%d", &a[i]);
    b[a[i]] = 1;
  }
  for (register int i = 1; i <= 600; i++)
    if (b[i]) ans++;
  printf("%d", ans);
  return 0;
}
