A small worm whose body length doubles every day, grows to 4 cm on the 15th day, and grows to 32 cm on the next few days.
一种小虫，体长每天长一倍，第15天长到了4厘米，第多少天长到32厘米．
<gadget id="calculator">15 + 1 + 1 + 1</gadget>
<output>18</output>

<result>18</result>