(defn neg [value]
  (* -1 value))

(defn invert [move]
  #((neg (get move 0))
     (neg (get move 1))))

(defn merge-moves [moves]
  (let [end-move #(0 0)]
    (for [move moves]
      (setv end-move
            #((+ (get end-move 0) (get move 0))
               (+ (get end-move 1) (get move 1)))))
    end-move))