print "\nAttempt 2\n";
my $count;
my $re2 = qr/^  (?{ $count = 0})
            (a (?{ $count++ }))*
            (??{"b{".$count."}"})
            (??{"c{".$count."}"})
          /x;

foreach my $str ( @strings ) {
  print "$str: ";
  print ($str =~ m/$re2/ ? "Accepted" : "Rejected","\n");
}