#!/usr/bin/perl -w
use strict;

# One array instead of 2x8 if statements
my @alphabets = 
(
"seklbvrfzijdqypcnowmtxuagh",
"elbtjpwdvzqaorfiyxnukmghsc",
"velukbiyxnordctjgpwhzqafms",
"orsdvejwmcbiyhfzlukxntqgpa",
"yxsdicvejqfbhmpluaorgkztwn",
"ejqyxsdkziurgtwcaovfbhmpln",
"jqyhcaxsdlkziuevfrgtwobmpn",
"atdvnsirekmfqhwobjclgypxuz" );

my $dec = $ARGV[0] && ($ARGV[0] eq '-d'); # are we decoding?
my ( $i, $out ) = ( 0, '' );
foreach ( split / /, <STDIN> ) {          # read and split a single line
    if ( $dec ) {
        eval "tr/$alphabets[$i]/a-z/";    # decoding tr///
                                          # We need eval because tr/// does
                                          # not allow for substitutions
    } else {
        tr/A-Z/a-z/;
        eval "tr/a-z/$alphabets[$i]/";    # encoding tr/// -- as above, 
                                          # just reversed
    }
    $out .= "$_ ";
    $i = ($i + 1) % @alphabets;  # this will walk through 0..7 circle
}

print "$out\n";