(defun cohere (w)
  (show (split (flat w))))

(defun flat (w &optional acc) 
  (cond ((null w) acc)
        ((atom w) (cons w acc))
        ((flat (car w) (flat (cdr w) acc)))))

(defun split (w &aux n m)
  (dolist (a w) (if (numberp a) (push a n) (push a m)))
  (list n m))

(defun show (w)
  ((lambda (n m)
     (if (< (reduce #'+ n)
            (reduce #'+ (mapcar #'char-code (mapcar #'(lambda (a) (char a 0)) m))))
         (remove-duplicates m :test #'string-equal)
         (remove-duplicates n)))
   (car w) (cadr w)))

(defun cohere (w)
  (show (split (flat w))))

(defun flat (w)
  (loop for a in w 
        if (and a (atom a)) collect a
        else nconc (flat a)))

(defun split (w &aux n m)
  (dolist (a w) (if (numberp a) (push a n) (push a m)))
  (list n m))

(defun show (w)
  ((lambda (n m)
     (if (< (reduce #'+ n)
            (reduce #'+
                    (mapcar #'char-code
                            (mapcar #'(lambda (a) (char a 0)) m))))
         (remove-duplicates m :test #'string-equal)
         (remove-duplicates n)))
   (car w) (cadr w)))

> (cohere '(1 ("a" ("b") 300) (1 "A"))) 
(300 1)