##
#!/usr/bin/perl -w
use strict;
use warnings;
use WWW::Mechanize;
use HTML::TreeBuilder;
use List::Util qw(max);
...
my $site = "http://www.hdwallpapers.in
/planes-desktop- wallpapers.html";
$mech->get($site);
my @links = map {$_->text} grep {$_->text =~ m/\d+/}
$mech->find_all_links();
print max @links;