A rectangular swimming pool, it takes 600 meters to walk around the swimming pool twice, what is the circumference of the swimming pool in meters?
一个长方形的游泳池，围着这个游泳池走两圈要走600米，这个游泳池的周长是多少米．
<gadget id="calculator">600 / 2</gadget>
<output>300</output>

<result>300</result>