9. (10%) A Mealy sequential circuit has five states; one input x; and one output y. Its state diagram is shown in the following figure. (a) (5%) Design the circuit with D flip-flops by treating the unused states as don't-care conditions. (b) (5%) Following (a), analyze the circuit obtained from the design to determine the effect of the unused states. 0.0 001 0/0 1/1 1/0 011 0/0 11 100 0/0 010 0/0 1/1 1/1 000