A project has eight activities: A, B, C, D, E, F, G, and H. Activities A, B can start anytime. Activity A takes 4 weeks, Activity B takes 2 week. Activity A must be completed before activity C and D can start. Activity C takes 4 weeks and activity D take 5 weeks. Activities E and F can start as soon as Activity B is completed and requires 5 weeks for Activity E and 6 weeks for F. Activities C and E must be completed before Activity G can start. Activity G takes 3 weeks. Activity F must be completed before Activity H can start. Activity H takes 4 weeks. What is the duration of the critical path? You need to show the flow map and work.