#| BEGIN (Write your solution here) |#
(define (even? number)
  (= (remainder number 2) 0))

(define (double n) (+ n n))

(define (halve n) (/ n 2))

(define (iter a b sum)
  (cond ((= b 0) sum)
        ((even? b) (iter (double a) (halve b) sum))
        (else (iter a (- b 1) (+ sum a))))
)

(
 define (mul-iter a b) (iter a b 0)
)
#| END |#