Cruise end and Great Wall?

Hi! Looking at traveling with our children on a cruise out of Hong Kong. We finish in Shanghai and was hoping to show them the Great Wall, then fly out of Beijing. Can we do that with the 144 hour visa? We were looking at a total of 3 days from end of cruise to flight from Beijing.
So fly into Hong Kong
Cruise
Cruise end in Shanghai
3 days Great Wall
Fly from Beijing