72 hour visa coming back in Beijing after a week from South Korea

i am going to china beijing from italy (i am italian) for one week, then i'm going to south korea for another week and coming back in beijing to take a flight to come back to italy (i'm going to stay 10 hours).
Can i take a 72 hour free transit when i come from south korea, and make a single entry one when i come from italy or do i have to make a double entry one?