A cylindrical material with a height of 2 decimeters is sawn vertically into two pieces along the diameter of the ground, and the surface area increases by 16 decimeters, what is the original volume of this piece of wood in cubic decimeters?
一根高2分米的圆柱体材料沿着地面直径垂直锯成两块，表面积增加了16平方分米，那么这根木料原来的体积是多少立方分米．
<gadget id="calculator">16 / 2 / 2</gadget>
<output>4</output>

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

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

<gadget id="calculator">3.14 * 4 * 2</gadget>
<output>25.12</output>

<result>25.12</result>