$($b$)$ Design a serial subtractor that will perform the operation $A-B,$ where

$A=a_{n-1}dots{a}_1{a}_0$ and $B=b_{n-1}dots{b}_1{b}_0.$ The operands are applied to the serial subtractor

sequentially, beginning with bits $a_0$ and $b_0.$ Use $J-K$ flip$-$flops in your design