sub PRINT {
   printf("\n\t\t%-10s %-10s %-10s\n",'UAS','LCV','DM');
   while(@UAS || @LCV || @DM) {
       my @args = map { (defined) ? split(' ') : ('','') }
                      shift(@UAS), shift(@LCV), shift(@DM);
       printf("\t\t" . '%3s  %-5s ' x 3 . "\n", @args);
   }
}