If a circle with a radius of 5 cm is divided into two semicircles, what is the sum of the circumferences of the two semicircles?
将一个半径为5厘米的圆分成两个半圆，这两个半圆的周长之和是多少厘米．
<gadget id="calculator">2 * 3.14 * 5</gadget>
<output>31.4</output>

<gadget id="calculator">5 * 2 * 2</gadget>
<output>20</output>

<gadget id="calculator">31.4 + 20</gadget>
<output>51.4</output>

<result>51.4</result>