(defun distanta(ar father_stack dist nod)
    (cond
        ((eq (car ar) nod) dist)
        ((= (car (cdr ar)) 2)(distanta (cdr (cdr ar)) (cons (+ dist 1) father_stack) (+ dist 1) nod))
        ((= (car (cdr ar)) 1)(distanta (cdr (cdr ar)) father_stack (+ dist 1) nod))
        ((= (car (cdr ar)) 0)(distanta (cdr (cdr ar)) (cdr father_stack) (car father_stack) nod))
    )
)