A piece of cylindrical wood is cut in half through the diameter of the bottom surface along the height, and the surface area is increased by 80 square centimeters. Given that the radius of the base of the cylinder is 5 cm, what is the volume of this piece of wood in cubic centimeters?
把一段圆柱形木料通过底面直径沿高切成两半，表面积增加80平方厘米．已知圆柱的底面半径5厘米，这根木料的体积是多少立方厘米．
<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<gadget id="calculator">5 * 2</gadget>
<output>10</output>

<gadget id="calculator">80 / 2 / 10</gadget>
<output>4</output>

<gadget id="calculator">3.14 * 25 * 4</gadget>
<output>314</output>

<result>314</result>