In a week I'm going to visit China and I'll stay there for a month. I've got a double entry visa.

Hi,
Firstly I'll enter from Vietnam and then I'd love to visit both Hong Kong and Makau (with only one entry left). If I go from Hong Kong to Makau by ferry and then come back to Hong Kong the same way and then enter China from Hong Kong will it count as one entry?
Thanks for your help,
Traveller :)