([rope move] (move-rope rope move 0 rope))
  ([rope move knot prev-rope]

  ([rope move] (move-rope rope move 0))
  ([rope move knot]

     (let [head (nth prev-rope knot)

     (let [head (nth rope knot)

           new-head (if (= knot 0) (update-position head move) (nth rope knot))

           new-head (if (= knot 0) (update-position head move) head)

       (recur (assoc rope knot new-head (inc knot) new-tail) move (inc knot) rope)))

       (recur (assoc rope knot new-head (inc knot) new-tail) move (inc knot))))