rectangular pillowcase is 5 decimeters long and 3 decimeters wide. How many decimeters of lace do you need to sew lace around it?
一个长方形的枕套，长5分米，宽3分米，给它的四周缝上花边，至少需要多少分米的花边？
<gadget id="calculator">5 + 3</gadget>
<output>8</output>

<gadget id="calculator">8 * 2</gadget>
<output>16</output>

<result>16</result>