# ex_09-1
# Learning Perl on Win32 Systems, Exercise 9.1

while () { ## NEW ##
  print "Enter first number: ";
  chomp($first = <STDIN>);
  last if $first eq "end"; ## NEW ##
  
  print "Enter second number: ";
  chomp($second = <STDIN>);
  last if $second eq "end"; ## NEW ##
  
  $message = &card($first) . " plus " .
    &card($second) . " equals " .
      &card($first+$second) . ".\n";
  print "\u$message";
} ## NEW ##

sub card {
  my %card_map;
  @card_map{0..9} = qw(
		       zero one two three four five six seven eight nine
		      );
  
  my($num) = @_;
  my($negative);
  if ($num < 0) {
    $negative = "negative ";
    $num = - $num;
  }
  if ($card_map{$num}) {
    $negative . $card_map{$num}; # return value
  } else {
    $negative . $num; # return value
  }
}