#!/usr/bin/perl -w
use strict;
my %names = (
        'john' => 'brown',
        'jacob' => 'black',
        'jingle' => 'gray',
        'heimer' => 'greene',
        'smitz' => 'purple' );
my %fullnames;
foreach my $firstname (keys %names) {
 $fullnames{$firstname . " " . $names{$firstname}} = 1;
}
print "$_\n" foreach (keys %fullnames);