Q2.23

A finite state machine with the following state table has a single input $x$ and a single out $z$.

$$\begin{array}{|c|ll|}\hline \textbf{present state} & \qquad \textbf{next state, z} \\ & \text{x=1} & \text{x=0} \\\hline \text{A} & \text{D,0} & \text{B,0} \\\hline \text{B} & \text{B,1} & \text{C,1} \\\hline \text{C} & \text{B,0} & \text{D,1} \\\hline \text{D} & \text{B,1} & \text{C,0} \\\hline \end{array}$$

If the initial state is unknown, then the shortest input sequence to reach the final state $C$ is: