use strict;
use warnings;

my %team;

while (defined (my $line=<DATA>)){
	chomp $line; # Zap the newline
	my ($name,$affiliation) = split /\t/,$line;
	next unless $affiliation; # Avoid empty lines
	push @{ $team{$affiliation} }, $name;
}

# Print the results
for my $aff (sort keys %team){
	print $aff, " :\t",
          join(", ", sort @{ $team{$aff} }) , "\n";
}


__DATA__
Obi Wan	Jedi
Yoda	Jedi
Count Dooku	Sith
Darth Vader	Sith
Luke Skywalker	Jedi

##</code><code>##

Jedi :	Luke Skywalker, Obi Wan, Yoda
Sith :	Count Dooku, Darth Vader