(define (reduce func lst init)
  (if (null? lst) init
      (reduce func (cdr lst) (func init (car lst)))))

(define (fib n)
   (define (fib1 n1 n2 k)
      (if (= k n) n2

          (fib1 n2
                (+ n1 n2)
                (+ k 1))))
   (if (= n 0) 0 (fib1 0 1 1)))