(define (towerofhanoi n) (transfer 'A 'B 'C n))

(define (movedisk from to)
 (list (list 'move 'disk 'from from 'to to)))

(define (transfer from to spare n)
 (cond ((equal? n 1) (movedisk from to))
       (#t (append (transfer from spare to (- n 1))
                     (append (movedisk from to)
                             (transfer spare to from (- n 1)))))))

(define (towerofhanoi n) (transfer (quote A) (quote B) (quote C) n))

(define (movedisk from to)
 (list (list (quote move) (quote disk) (quote from) from (quote to) to)))

(define (transfer from to spare n)
 (cond ((equal? n 1) (movedisk from to))
       (#t (append (transfer from spare to (- n 1))
                     (append (movedisk from to)
                             (transfer spare to from (- n 1)))))))

(define (countatoms l)
   (cond ((null? l) 0)
         ((symbol? l) 1)
         (#t (+ (countatoms (car l))
                (countatoms (cdr l))))))

(define (countatoms l)
   (cond ((null? l) 0)
         ((symbol? l) 1)
         (else (+ (countatoms (car l))
                (countatoms (cdr l))))))