Do I require a pre visa if I have 26 hours of transit time including Nanjing and Kunming

I am a Canadian Citizen and I am traveling from Canada to Nepal. I have stop over first in Nanjing and then in Kunming. Total time I will be spending between the time I enter in Nanjing and I leave Kunming is about 26 hours (total transit time including Two cities is more than 24 hours). Does 72 hours free transit policy apply to that situation or I have to apply pre visa?