my %largest;

while (<>) {
   my ($item, $group_id, $count) = split;

   next if $largest{$group_id}
        && $largest{$group_id}[2] >= $count;

   $largest{$group_id} = [ $item, $group_id, $count, $_ ];
}

for (values(%largest)) {
   print($_->[-1]);
}