foreach $unicode (keys %from) {
    if (defined($to{$unicode})) {
        if ($from{$unicode} ne $to{$unicode}) {

            my $fromchar = $from{$unicode};
            my $fromchar =~ s/0x(..)/pack('c',hex($1))/ge;

            $tochar = $to{$unicode};
            $tochar =~ s/0x(..)/pack('c',hex($1))/ge;

            $wrong = $wrong . $fromchar;
            $right = $right . $tochar;
        }
    }
}