Using a switch$-$tail structure design the following: a$)$ an $8-$bit counter with only one bit set to

zero at any time. The rest of the bits are $1($i$.$e$.,01111111,10111111,11011111...).$ b$)$ an $8-$bit

counter having $2$ adjacent bits set to one at any point. The rest of the bits are set to zero $($i$.$e$.,$

$11000000,01100000,00110000...).$