A rectangular swimming pool is 120 meters long, and its width is 70 meters less than its length. If you walk along the edge of the swimming pool twice, how many meters will you walk in total?
一个长方形游泳池长120米，宽比长少70米，沿游泳池边走两圈，一共走了多少米？
<gadget id="calculator">120 - 70</gadget>
<output>50</output>

<gadget id="calculator">120 + 50</gadget>
<output>170</output>

<gadget id="calculator">170 * 2 * 2</gadget>
<output>680</output>

<result>680</result>