#include <bits/stdc++.h>
using namespace std;
int main() {
  int a[610] = {0}, n, m, i, j, k;
  scanf("%d", &n);
  m = 0;
  for (i = 0; i < n; i++) {
    scanf("%d", &k);
    if (m < k) m = k;
    a[k]++;
  }
  j = 0;
  for (i = 1; i <= m; i++) {
    if (a[i] > 0) j++;
  }
  printf("%d\n", j);
  return 0;
}
