A rectangular pillowcase, 40 cm long and 30 cm wide, with lace embroidered around it, how many centimeters is the lace long?
一个长方形枕套，长40厘米，宽30厘米，四周绣上花边，花边长多少厘米？
<gadget id="calculator">40 + 30</gadget>
<output>70</output>

<gadget id="calculator">70 * 2</gadget>
<output>140</output>

<result>140</result>