sub binary {
  my ($n) = @_;
  return $n if $n == 0 || $n == 1; 
  my $k = int($n/2);
  my $b = $n % 2;
  print "n is $n.\nk is $k.\nb is $b.\n";
  print "above\n";
  my $E = binary($k);
  print "below\n";
  print "n is $n.\nE is $E.\n\n";
  return $E . $b;
}

print binary(8);