#!/usr/bin/perl
use strict;
use warnings;

my @lines;

while(<>){
 push @lines, $_;
}

while(@lines){
 print flip_line(pop @lines);
}

sub flip_line 
{rev_string(join '', map flip_char($_), split //, shift)}

sub rev_string 
{scalar reverse shift}

sub flip_char 
{$_= lc shift; tr/'ahbbmfnnjpdrvutwqgye'/'eyqgwtuvrdpjnnfmbbha'/; $_}

##</code><code>##

some text can be
flipped over using
this script

##</code><code>##

fdijcs siyf
buisn jano paddilt
aq uec fxaf awos

##</code><code>##

./umop-apisdn.pl < test.txt | ./umop-apisdn.pl