A circular flower bed with a circumference of 80 meters, a pot of orchids every 4 meters, and a pot of roses in the middle of every two pots of orchids, how many pots of flowers are needed in total.
一圆形花台，周长80米，每隔4米摆一盆兰花，每两盆兰花中间摆一盆月季花，共需要多少盆花．
<gadget id="calculator">80 / 4</gadget>
<output>20</output>

<gadget id="calculator">20 * 2</gadget>
<output>40</output>

<result>40</result>