use strict;
use warnings;

##</code><code>##

use strict;
use warnings;
use HTML::TreeBuilder;
my $HTML_to_parse = shift (@ARGV);
my $tree = HTML::TreeBuilder->new;
$tree->parse($HTML_to_parse);
$tree->eof;

my @paragraph_tags = $tree->look_down('_tag', 'p');
foreach my $p (@paragraph_tags) {
  # note that this variable will "hide" the other
  # copy of @paragraph_tags and be garbage collected
  # as soon as it goes out of scope (the end of the
  # while loop)
  my @paragraph_tags = $p->look_down('_tag', 'p');
  if (scalar (@paragraph_tags) == 1) {
    my $tag = shift (@paragraph_tags);
    my @contents = $tag->content_list;
    my $content = "";
    foreach my $con (@contents) {
      # check that we have text and not an object
      $content .= $con unless (ref $con);
    }
    print $content;
  }
}

##</code><code>##

<p class="foo">This is <p class="bar">HTML code using CSS Style sheets.</p></p>