#!/usr/bin/env perl -l

use strict;
use warnings;

my @pairs = (['CHARLIE ROOT', 'HARRY NODE'], ['abc1', 'cde1']);

print get_non_shared(reverse @$_), ' ', get_non_shared(@$_) for @pairs;

sub get_non_shared {
    my ($ref, $src) = @_;
    my %ref_char = map { $_ => 1 } grep { /\p{Alpha}/ } split '' => $ref;
    join '' => grep { ! $ref_char{$_} } split '' => $src;
}