Xiaodong swam 5 laps around a swimming pool that is 30 meters long and 20 meters wide. How many meters did he swim in total?
小东沿着长30米，宽20米的游泳池四周游了5圈，他一共游了多少米？
<gadget id="calculator">30 + 20</gadget>
<output>50</output>

<gadget id="calculator">50 * 2 * 5</gadget>
<output>500</output>

<result>500</result>