can I go to china and back with 144 hour exempt visa?

Trying to understand: It is not clear for me if I can legally do the following booking and travelling with no visa, using 144 hour exemption:
HKG / HZG/ HKG (I will be staying just 4 days)
Or , as an alternative,
Frankfurt / PVG/ HZG/ PVG/ Frankfurt.. same time frame, 4 days .
My passport is italian.
Thanks