What does this code do$?$

$$ int d;

$$ do $\{$

$$ printf$("$Enter a number:"$)$;

$$ scanf$("\%$d$",$ &d$)$;

$$ switch $($d$)\{$

$$ case $1$:

$$ case $2$:

$$ case $3$:

$$ case $4$:

$$ printf$("$

$\%$d

$",$ d$)$;

$\}$

$\}$ while $($d $!=4)$;