#!/usr/bin/env perl

use strict;
use warnings;

our %code;

while (<>){
	chomp;
	my @tokens = split " ", $_;
	my $protein = shift @tokens;
	for my $token (@tokens) {
	    $code{$token} = $protein;
	}
}

foreach my $key (sort keys %code){
	print "$key\t$code{$key}\n";
}

##</code><code>##

A ABC DEF GHI JKL
B QRS TUV WXY
C EYE LUV YOU

##</code><code>##

ABC	A
DEF	A
EYE	C
GHI	A
JKL	A
LUV	C
QRS	B
TUV	B
WXY	B
YOU	C