#!/usr/bin/perl

# http://perlmonks.org/?node_id=1143273

use strict;
use warnings;

my @dirs = qw( 
  12112014
  01052015
  02202015
  03102015
  01012011
  04092015
  09092015
  );  

my $latest = (sort { $a % 1e4 <=> $b % 1e4 } sort @dirs)[-1];

print "latest dir $latest\n";