use strict;
use warnings;
use XML::LibXML;

foreach my $filename (@ARGV) {
  my $parser = XML::LibXML->new();
  my $doc    = $parser->parse_file($filename);
  foreach my $person ($doc->findnodes('/edgarSubmission/relatedPersonsList/relatedPersonInfo/relatedPersonName')){ 
    print $_->data . " " for $person->findnodes('firstName/text()');    
    print $_->data . " " for $person->findnodes('lastName/text()');    
    print "\n";
  }
}