A rectangular reed mat with a length of 12.56 meters and a width of 3 meters is used to enclose a cylindrical grain storage with the length as the perimeter of the bottom surface (the consumption of joints is not counted), how many cubic meters is the volume of the enclosed grain storage?
把一张长12.56米、宽3米的长方形苇席，围成以长为底面周长的圆柱形粮囤(接头消耗不计)，这个围成的粮囤的容积是多少立方米？
<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 * 3</gadget>
<output>37.68</output>

<result>37.68</result>