There is a wall clock, the minute hand is 50 cm long, what is the length of the tip of the minute hand making one revolution?
有一个挂钟，分针长50厘米，分针的尖端转一圈的长度是多少．
<gadget id="calculator">2 * 3.14 * 50</gadget>
<output>314</output>

<result>314</result>