A cylinder is surrounded by a rectangular iron sheet with a length of 12.56 decimeters and a width of 6.28 decimeters. What is the maximum volume of the cylinder surrounded by cubic decimeters?
用一张长12.56分米，宽6.28分米的长方形铁皮围成一个圆柱，围成的圆柱的最大体积是多少立方分米．
<gadget id="calculator">12.56 / 3.14 / 2</gadget>
<output>2</output>

<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">3.14 * 4 * 6.28</gadget>
<output>78.8768</output>

<result>78.8768</result>