; man or boy

(define (a k x1 x2 x3 x4 x5)
  (define (b)
    (set! k (- k 1))
    (a k b x1 x2 x3 x4))
  (if (<= k 0)
      (+ (x4) (x5))
      (b)))
      
(do ((k 1 (+ k 1))) ((< 12 k))
  (display k) (display ": ")
  (display (a k (lambda ()  1)
                (lambda () -1)
                (lambda () -1)
                (lambda ()  1)
                (lambda ()  0)))
  (newline))