SIN-CTU-HKG-SGN free visa in Chengdu

hi all

will the above routing be accepted for free transit?

SIN-CTU-HKG ( 1 or 2 airlines (airline A (SIN-CTU-HKG) or Airline A (SIN-CTU) +B)(CTU-HKG)
HKG-SGN (1 airline (airline C))

stay lengths :

CTU = 72 hours
HKG = 48 hours or must only transit hkg being final destination . then another flight HKG-SGN 2 days later

let me know
cheers