A rectangular pillowcase, 6 decimeters long and 5 decimeters wide. How many decimeters of lace should be used to sew lace on the four sides?
一个长方形枕套，长6分米，宽5分米．四边缝上花边，要用多少分米的花边？
<gadget id="calculator">6 + 5</gadget>
<output>11</output>

<gadget id="calculator">11 * 2</gadget>
<output>22</output>

<result>22</result>