The precedence diagram below shows a production process where each step (letters A H) takes one minute to complete. The process operates for 9 hours each day and must produce 220 units in that time. Workstations are going to be used, in order to keep the number of operators as small as possible. What's the maximum number of steps that can be assigned to any single workstation? A single workstation can have at most step(s) assigned to it