die "Required argument missing!\n" unless ($ARGV[0]);
my $response;
if ($ARGV[0] =~ /Hello/i) {
  $response = "Hello to you.\n";
}else{
  $response = "Huh?\n";
}
print $response;

##</code><code>##

die "Required argument missing!\n" unless ($ARGV[0]);
{ #scoping block
  my $response;
  if ($ARGV[0] =~ /Hello/i) {
    $response = "Hello to you.\n";
  }else{
    $response = "Huh?\n";
  }
  print $response;
}