In Racket Programming language, write a function that is mutually recursive. The function should be defined as (length-str listof-strings), with only a list of strings as its only argument. This function will return an n-list that has the same shape as "listof-strings", where each string in the list is replaced by the length of that string. "length-str" must be a mutually recursive function that uses another funciton called "length-helper" that processes the string expression. ex : > '("hello" "from" ("the" "other") "side") returns : '(5 4 (3 5) 4)