"Design a sequential circuit with two T flip-flops A and B, and one input x. When x = 0, the circuit remains in the same state. When x = 1, the circuit goes through the state transitions from 00 to 01, to 10, to 11, back to 00, and repeats. What is the boolean equation of the input of flip-flop A (TA)? Type variables and operations without blanks."