#!/usr/bin/perl
use warnings;
$a = "A9"; print ++$a, "\n";
$a = "bz"; print ++$a, "\n";
$a = "Zz"; print ++$a, "\n";
$a = "z9"; print ++$a, "\n";
$a = "9z"; print ++$a, "\n";

##</code><code>##

>perl auto2.plx
B0
ca
AAa
aa0
10
>