In the following block diagram $x$ and $Y$ are two inputs, and $Z$

is output. $x$ and $Y$ are digital signals. Design a circuit that if

$x$ leads $Y,$ the output $Z$ is $1$ ; if $Y$ leads $x,$ the output $Z$ is $0.$

$x$ leading $Y$

$Y$ leading $x$

Note that $x$ and $Y$ cannot arrive

at the same time.