Xiao Fang took a hound to ride a bicycle to Moshan Xiaoyou, 25.2 kilometers away. He was cycling at a speed of 18 kilometers per hour, and the speed of the hound was twice the speed of the car. When the hound reaches the foot of Moshan Mountain, if Xiao Fang has not arrived yet, it will immediately return and run to meet Xiao Fang. After meeting Xiaofang, run back to Moshan... run back and forth like this until Xiaofang reaches Moshan. In this way, how many kilometers did the hound run in total?
小方带着一条猎犬骑车离家到25.2千米远的磨山效游，他骑车速度是每小时18千米，猎犬奔跑的速度是车速的2倍．当猎犬跑到磨山脚下后，如小方还未到，则马上返回迎着小方跑去．遇到小方后再跑回磨山…这样来回跑一直到小方到磨山为止．这样，这只猎犬一共跑了多少千米路．
<gadget id="calculator">25.2 / 18</gadget>
<output>1.4</output>

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

<gadget id="calculator">1.4 * 36</gadget>
<output>50.4</output>

<result>50.4</result>