use XML::Twig;

my $twig=XML::Twig->new(   
    twig_handlers => 
      { title   => sub { $_->set_gi( 'h2') }, #  tags to h2
        para    => sub { $_->set_gi( 'p')  }, #  para to p
        populate=> sub { while (<>)
{ if (%Items !~ m/"<us:"|"<oa:"(.*)/) { $Items{$1} =1}  
else {$Items{$2} =($Items{$1}+(/$1/))
}

#If element is not in the hash, adds it 
#If element is in the hash, adds the number of matches to the value 
    					 };
    					}, 		  
    hidden  => sub { $_->delete;       }, # remove hidden elements
    list    => \&my_list_process,         # process list elements
    div     => sub { $_[0]->purge;     }, # free memory
      },
      );
                    
$twig->parsefile( 'bigXMLfile.xml'); # build it
print %Items;                        # output the twig
$twig->purge;                  # clear end of document from memory