(define survives?
  (lambda (position people)
    (or (= people 2)
        (and (not (= position 3))
             (survives? (remainder (- (+ position people) 3)
                                   people)
                        (- people 1))))))

(define first-surviving-after
  (lambda (position people)
    (let ((next (+ position 1)))
      (if (survives? next people)
          next
          (first-surviving-after next people)))))

(define good-spots
  (lambda (people)
    (let ((first-spot (first-surviving-after 0 people)))
      (let ((second-spot (first-surviving-after first-spot people)))
        (list first-spot second-spot)))))