I need help using PuTTY.

Write a Lisp function that goes through a list and calculates the sum of the even numbers in the list no matter how deep they are in the list. So$,$ it needs to do this recursively.$$

Examples:$$

$($sum$-$even $\text{'}(139112355))$ should return $0$

$($sum$-$even $\text{'}(281561214133))$ should return $42$

$($sum$-$even $\text{'}(1234(56(278)(122310)1)23(124)))$ should return $52.$