use strict;
use warnings;

my %aas = (
    'serine' => ['TCA', 'TCC', 'TCG', 'TCT'],
    'proline' => ['CCA', 'CCC', 'CCG', 'CCT'] 
);

my %codes;
$codes{'earth'} = \%aas;
$codes{'mars'} = {
	'serine' => ['QWZ', 'QWX', 'QWW'],
	'proline' => ['ZXZ', 'ZXX', 'ZXQ', 'ZXW'] 
};
	
base_code (\%codes);

sub base_code {
    my $h_ref = $_[0];
    for my $planet (keys %$h_ref){
        for my $aa (keys %{ $h_ref->{$planet} }){
            for my $codon (@{ $h_ref->{$planet}{$aa} }){
                print $codon, "\n";
            }	
        }
    }
}


##</code><code>##

CCA
CCC
CCG
CCT
TCA
TCC
TCG
TCT
ZXZ
ZXX
ZXQ
ZXW
QWZ
QWX
QWW