(define (is-even? n)
  (= (remainder n 2) 0))
(define (square x)
  (* x x))
(define (fast-expt-iter a b n)
  (if (= n 0)
      a
      (fast-expt-iter (* a (square b)) b (- n 2))))
(define (solution b n)
  (if (is-even? n)
      (fast-expt-iter 1 b n)
      (* b (fast-expt-iter 1 b (- n  1)))))