A court is 30 meters long and 20 meters wide. If Tintin walks twice along the court, how many meters will he walk in total?
一个球场长30米，宽20米，丁丁沿球场走两圈，一共走多少米米．
<gadget id="calculator">30 + 20</gadget>
<output>50</output>

<gadget id="calculator">50 * 2 * 2</gadget>
<output>200</output>

<result>200</result>