#!/usr/bin/perl -040l

# http://perlmonks.org/?node_id=1197777

use strict;
use warnings;

my @alphabet = (0..9, 'a'..'z');
my %next;
@next{@alphabet} = @alphabet[1..$#alphabet];

$_ = '0zyw'; # let's start at some place interesting

for my $n ( 1..200 )
  {
  print;
  s/(.)(z*)$/ $next{$1} . $2 =~ tr!z!0!r /e; # advance
  }