I will be flying from Denpasar to Shanghai, where I will have a 14 hour layover,

then from Shanghai to Kunming, where I have an 8 hour layover, then from Kunming to San Francisco. I only want to use the 72 hour free transit for Shanghai, but as I read it, from Shanghai I would have to go to a third country as opposed to having a ticket for a different flight. Please let me know as I don't think I can do a super long layover in Shanghai airport, since there's nothing there. I would prefer to use the 72 free transit, but will get a regular tourist visa if needed.