python code

$```$

def sum$\_$proper$\_$divisors$($n: int$)->$ int:

$"""$Returns the sum of the proper divisors of n$.$

Requires: n $>0$

$"""$

total $=0$

d $=$ l

while d $$ n:

if n $\%$ d $==0$:

total $=$ total $+$ d

d $+=1$

return total

$```$

Rewrite the function sum$\_$proper$\_$divisors without using any loops. Use recursion only. You may add parameters to the function but they must be default parameters.