(define (fooBar l1 l2)

  (define (foo1 x y lst1 list2)
    (cond
      ((and (null? list1) (null? list2)) null)
      ((null? list1) (foo2 y y list1 list2))
      ((= x 0) (cons (car list1) (foo2 (+ y 1) (+ y 1) (cdr list1) list2)))
      (else (cons (car list1) (foo1 (- x 1) y (cdr list1) list2))))))

  (define (foo2 x y list1 list2)
    (cond
      ((and (null? list1) (null? list2)) null)
      ((null? list2) (foo1 y y list1 list2))
      ((= x 0) (cons (car list2) (foo1 (+ y 1) (+ y 1) list1 (cdr list2))))
      (else (cons (car list2) (foo2 (- x 1) y list1 (cdr list2))))))

  (foo1 0 0 l1 l2))