#!/usr/bin/perl

use warnings;
use strict;

my $text1 = 'aapnootmies';
my $text2 = 'aapnogeenaap';

my $text3 = $text1 . reverse($text2);

$text3 =~ m/(.*)(.*)(??{quotemeta reverse $1})/s;
my $common = $1;
$text1 =~ s/^\Q$common//;
$text2 =~ s/^\Q$common//;

print "[$text1]\n[$text2]\n";