use strict;
use XML::Twig;

my $string = '<xml>
<p>here the paragraph comes</p>
<p>here the paragraph comes</p>
<p>here the paragraph comes</p>
<p>here the paragraph comes</p>
<a>here the paragraph comes</a>
<a>here the paragraph comes</a>
<a>here the paragraph comes</a>
<a>here the paragraph comes</a>
<a>here the paragraph comes</a>
<a>here the paragraph comes</a>
<a>here the paragraph comes</a>
<a>here the paragraph comes</a>
<a>here the paragraph comes</a>
<a>here the paragraph comes</a>
<a>here the paragraph comes</a>
<a>here the paragraph comes</a>
</xml>';

my $twig = new XML::Twig(
					
		twig_handlers => {
											p => sub { $_->add_id() } #generate id
											a => sub { $_->add_id() }, #generate id
					
										 },
		pretty_print => 'indented' #print format
);

#my $twig1 = new XML::Twig(
#					
#		twig_handlers => {
#												a => sub { $_->add_id() } #generate id
#										 },
#		pretty_print => 'indented' #print format
#);


$twig->set_id_seed( "fig" );
$twig->parse($string);
$string = $twig->sprint;

#$twig1->set_id_seed( "sec" );
#$twig1->parse($string);
#$string = $twig1->sprint;

print $string;