road is 1200m long. Xiao Ming and his puppy start from the starting point of this road at the same time at a uniform speed. When Xiao Ming runs to (1/3) of this road, the puppy has already run to this road the end of the road. Then the puppy immediately returns to meet Xiao Ming, runs towards the finish line after meeting Xiao Ming, and immediately returns to meet Xiao Ming when it reaches the finish line...until Xiao Ming reaches the finish line. How many meters has the puppy run since it started?
一条路长为1200m，小明和他的小狗分别以均匀的速度同时从这条路的起点出发，当小明跑到这条路的(1/3)处的时候，小狗已经跑到这条路的终点．然后小狗立即返回与小明相向而行，遇到小明以后再跑向终点，到达终点后再立即返回与小明相向而行…直到小明达终点．小狗从出发开始，一共跑了多少米？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 / (1/3)</gadget>
<output>3</output>

<gadget id="calculator">1_200 * 3</gadget>
<output>3_600</output>

<result>3_600</result>