Critical path

For the given information kindly find the critical path and also help in calculating the project completion time Work Q / Predecessors none / Duration 1 dayWork R / Predecessors Q / Duration 4 daysWork S / Predecessors Q / Duration 2 daysWork T / Predecessors Q / Duration 2 daysWork U / Predecessors T / Duration 3 daysWork V / Predecessors T / Duration 3 daysWork W / Predecessors U / Duration 2 daysWork X / Predecessors V,W / Duration 1 dayWork Y / Predecessors S,X / Duration 3 daysWork Z / Predecessors R / Duration 2 days