(define (yamada)
  (list "yamada" nouryoku))

(define (is-yamada? yamada)
  (if (= (car yamada) "yamada")
      yamada
      nil))

(define (majo)
  (list "majo" nouryoku))

(define (is-majo? majo)
  (if (= (car majo) "majo")
      majo
      nil))

(define (copy yamada majo)
  (if (is-yamada? yamada)
      (if (is-majo? majo)
          (define (car (cdr (yamada)))
            (car (cdr (majo)))))))

(define (kiss someone the-other)
  (cond ((and (is-yamada? someone)
              (is-majo? the-other))
         (begin
           (copy someone the-other)
           (car (cdr someone) the-other)))
        ((and (is-majo? someone)
              (is-yamada? the-other))
         (begin
           (copy the-other someone)
           (car (cdr the-other) someone)))
        ((and (or (is-yamada? someone)
                  (is-majo? someone))
              (or (= nil (is-yamada? the-other))
                  (= nil (is-majo? the-other))))
           (car (cdr someone) the-other))
        ((and (or (is-yamada? the-other)
                  (is-majo? the-other))
              (or (= nil (is-yamada? someone))
                  (= nil (is-majo? someone))))
         (car (cdr the-other) someone))))