A caterpillar grows from a larva to an adult, and doubles in size every day. On the 24th day, it grows to 20 cm. When it grows to 5 cm, it is the first day.
一条毛毛虫从幼虫长到成虫，每天长大一倍，第24天时长到20厘米，当它长到5厘米时是第多少天．
<gadget id="calculator">24 - 1 - 1</gadget>
<output>22</output>

<result>22</result>