#!/usr/bin/perl

use warnings;
use strict;

print ieronim_pure();

sub ieronim_pure {
    #my @cubes = qw/pgpygr rprrgy ppryyg rrygpy/;
    my @cubes = qw/rprrgy ppryyg rrygpy/;
    my %seen;
    my $str = join("", map {$_, scalar reverse $_} "pgpy","ggry","pygr")
                ."!".join "!", 
                map { join "", grep {!$seen{$_}++} map {join "", @$_} @$_} 
                map { [ rotate([@{$_}[0,1,2,3]]),
                        rotate([@{$_}[4,1,5,3]]),
                        rotate([@{$_}[0,4,2,5]]) ] } map { [split //] } @cubes;

    my @result;
    my $re = qr/^(?:[^!]{4})*
                 (?:
                    ([^!])
                    ([^!])
                    ([^!])
                    ([^!])
                 )
                 (?:[^!]{4})*!
                 (?:[^!]{4})*
                 (?:
                    (?!\1)([^!])
                    (?!\2)([^!])
                    (?!\3)([^!])
                    (?!\4)([^!])
                 )
                 (?:[^!]{4})*!
                 (?:[^!]{4})*
                 (?:
                    (?!\1|\5)([^!])
                    (?!\2|\6)([^!])
                    (?!\3|\7)([^!])
                    (?!\4|\8)([^!])
                 )
                 (?:[^!]{4})*!
                 (?:[^!]{4})*
                 (?:
                    (?!\1|\5|\9)([^!])
                    (?!\2|\6|\10)([^!])
                    (?!\3|\7|\11)([^!])
                    (?!\4|\8|\12)([^!])
                 )(?{
                    push @result, [join("", $1,$2,$3,$4), 
                                   join("", $5,$6,$7,$8), 
                                   join("", $9,$10,$11,$12),
                                   join("", $13,$14,$15,$16)]
                })
                (?!)
                /x;
    #print $str;

    $str =~ /$re/;
    return map { join "\n", @$_, "", ""} @result;
}


sub rotate {
    my @strips;
    $strips[0] = shift;
    $strips[1] = [reverse @{$strips[0]}];
    my @rotated;
    foreach (0..$#{$strips[0]}) {
        foreach my $strip (@strips) {
            push @$strip, shift @$strip;
            push @rotated, [@$strip];
        }
    }
    return @rotated;
}