Design a logic circuit that controls an elevator door in a three-storied building. The circuit shown in the figure has four inputs. M is a logic signal that indicates when the elevator is moving (M=1) or stopped (M=0). F1,F2 and F3 are floor indicators signals that are normally LOW, and they go HIGH only when the elevator is positioned at the level of that particular floor. For example, when the elevator is lined up with the second floor, F2=1 and F1=F3=0.The circuit output is the OPEN signal which is normally LOW and is to go HIGH when the elevator door is to be opened. M F1 F2 F3 III ELEVATOR CIRCUIT OPEN