;please solve it as soon as possible :)

5-16) Design a sequential circuit wit twp D Flip-Flops, A and B, and one input x. When x = 0, then the state of the circuit remains the same. When x = 1, the circuit goes through the state transitions from 00 to 01 to 11 to 10 back to 00, and repeats. 5-17) Design a one input, one output serial 2s complimenter. The circuit accepts a string of bits from the input and generates the 2's compliment at the output. The circuit can be reset asynchronously to start and end the operation. 5-19) A sequential circuit has three flip-flops A, B, C, one input x; and one output, y. The state diagram is shown in Fig.P5-19. The circuit is to be designed by treating the unused states as don't care conditions. Analyze the circuit obtained from the design to determine the effect of the unused states. a) Use D flip-flops in the design b) Use J-K flip-flops in the design 0/0 001 0/0 1/1 1/0 011 0/0 1/1 100 0/0 010 0/0 11 1/1 000