To place flowerpots on the edge of a pentagonal flower bed so that there are 6 potted flowers on each side, how many potted flowers are needed at least.
要在五边形的花坛边上摆上花盆，使每一边都有6盆花，最少需要多少盆花．
<gadget id="calculator">6 - 1</gadget>
<output>5</output>

<gadget id="calculator">5 * 5</gadget>
<output>25</output>

<result>25</result>