US and Canadian passports visiting Hong Kong - Shanghai - Beijing

Hello,
We are planning to be in Hong Kong on July 31.
On Aug 4, we will fly from Hong Kong direct to Shanghai (Pudong).
On Aug 6, we will fly from Shanghai (Pudong) direct to Beijing.
On Aug 8, we will fly from Beijing direct to Hong Kong.
Does this itinerary fit the criteria for the 72 hour free transit in Beijing and 144 hour free transit in Shanghai?
Do we have to still apply for visa?
Thank You.