Xiao Wei rode a hunting dog away from home to Zhaobao Mountain, which was 36 kilometers away, for an outing. He was riding at a speed of 18 kilometers per hour, and the running speed of the hunting dog was twice the speed of the bicycle. When the hunting dog reaches the foot of Zhaobao Mountain, if Xiaowei has not yet arrived, it will immediately go back and run to meet Xiaowei, and then run to Zhaobaoshan after meeting Xiaowei... and run back and forth until Xiaowei reaches Zhaobaoshan. At this time, how many kilometers did the hound run in total?
小巍带着一条猎狗骑车离家到36千米远的招宝山郊游，他骑车速度是每小时18千米，猎狗奔跑速度是骑车速度的2倍．当猎狗跑到招宝山脚下后，如小巍还未到，则马上返回迎着小巍跑去，遇到小巍后再跑向招宝山…这样来回跑一直到小巍到招宝山为止．这时，这只猎狗一共跑了多少千米路？
<gadget id="calculator">36 / 18</gadget>
<output>2</output>

<gadget id="calculator">18 * 2</gadget>
<output>36</output>

<gadget id="calculator">2 * 36</gadget>
<output>72</output>

<result>72</result>