Total project duration?

What is the project total duration? Prepare a LOB schedule for the construction of 40 typical floors of a high-rise commercial building. A precedence schedule showing the sequence of a typical floor construction is given in the below Figure. Each activity will be performed by one crew of subcontractors. Durations are in days. Add time buffer zone of zero between activities. C.6 E.8 A.4 B.4 F.4 D.3