#!/usr/bin/perl -w

use strict;

my $seen = 0;

while (<DATA>) {
  chop;
  my ($id, $maker, $make) = split(",", $_);
  if ($id != $seen) {
    print "$id. $maker\n";
    print "   - $make\n";
    $seen = $id;
  } else {
    print "   - $make\n";
  }
}

__DATA__
1,gm,saturn
1,gm,chevy
1,gm,caddy
2,ford,taurus
2,ford,escort
3,vw,bug
3,vw,jetta
3,vw,phaeton