rectangular road sign is 2 meters long and half the width, what is the circumference in meters?
一个长方形路标，长2米，宽是长的一半，周长是多少米．
<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<gadget id="calculator">2 + 1</gadget>
<output>3</output>

<gadget id="calculator">3 * 2</gadget>
<output>6</output>

<result>6</result>