So that means we either have two ring structures, zero Pi bonds, one ring structure, or one Pi bond, or two Pi bonds and zero ring structures. Let's put an equal sign here. Example number five. So in this compound we now have six N. So our carbon number is six. We have eight HS, but we also have two BRS and three oxygens. Recall that whenever we see an oxygen or a sulfur, according to rule number two, we do not count them.