Put potted flowers on the edge of a square flower bed, so that there are 6 boxes on each side, at least how many boxes should be placed.
在一个正方形的花坛边上摆盆花，要使每边上都有6盒，至少要摆多少盒．
<gadget id="calculator">6 * 4</gadget>
<output>24</output>

<gadget id="calculator">24 - 4</gadget>
<output>20</output>

<result>20</result>