my %h;
  for my $file ( glob "*.[abc]" )
  {
    my( $file_k0, $file_k1 ) = $file =~ /(.*)\.(.*)/;
    local @ARGV = ($file);
    while (<>)
    {
      chomp;
      push @{ $h{$file_k0}{$file_k1} }, [ split /\t/ ];
    }
  }

##</code><code>##

  for my $file_k0 ( sort keys %h ) {
    for my $file_k1 ( sort keys %{ $h{$file_k0} } ) {
      print "File $file_k0.$file_k1 -\n";
      for my $line_ar ( @{ $h{$file_k0}{$file_k1} } ) {
        for my $field ( @$line_ar ) {
          print "\t$field";
        }
        print "\n";
      }
    }
  }