(define (Sol1 func tree)
  (if (empty? tree) '()
      (list (func (car tree)) (Sol1 func (cadr tree)) (Sol1 func (caddr tree)))))


(define (leaf? tree)
  (and (empty? (cadr tree)) (empty? (caddr tree))))

(define (RemoveOneDeviant tree)
  (if (empty? tree) '()
      (cond
        ((and (empty? (cadr tree)) (empty? (caddr tree))) (list (car tree) (RemoveOneDeviant (cadr tree)) (RemoveOneDeviant (caddr tree))))
        ((empty? (caddr tree)) (list (caadr tree) (RemoveOneDeviant (cadadr tree)) (RemoveOneDeviant (car (cddadr tree)))))
        ((empty? (cadr tree)) (list (caaddr tree) (RemoveOneDeviant (car (cdaddr tree))) (RemoveOneDeviant (cadr (cdaddr tree)))) )

        (else (list (car tree) (RemoveOneDeviant (cadr tree)) (RemoveOneDeviant (caddr tree)))) )))

(define (everyboth tree)
(if (leaf? tree)
#t
(and (not (or (null? (cadr tree)) (null? (caddr tree)))) (everyboth (cadr tree)) (everyboth (caddr tree)))))

(define (Sol3 tree)
  (define (computing tree1)
    (if (everyboth tree1) tree1
        (computing (RemoveOneDeviant tree1))))
  (if (empty? tree) null
      (if (and (not (empty? (cadr tree))) (empty? (caddr tree))) (list (car tree) (computing (cadr tree)) null)
          (if (and (empty? (cadr tree)) (not (empty? (caddr tree)))) (list (car tree) null (computing (caddr tree)))
              (computing tree)))))