If you walk around a rectangular artificial lake with a length of 500 meters and a width of 200 meters, what is the total distance traveled in meters?
绕着长为500米，宽为200米的长方形人工湖走一圈，走的总路程是多少米．
<gadget id="calculator">500 + 200</gadget>
<output>700</output>

<gadget id="calculator">700 * 2</gadget>
<output>1_400</output>

<result>1_400</result>