A cylindrical wood with a length of 2 meters, after cutting off a small cylindrical piece of wood with a length of 2 decimeters, the surface area is reduced by 12.56 square decimeters, so what is the original volume of this wood?
一根长2米的圆柱形木头，截去2分米长的一段圆柱形小木块后，表面积减少了12.56平方分米，那么原来这根木头的体积是多少？
<gadget id="calculator">12.56 / 2 / 3.14 / 2</gadget>
<output>1</output>

<gadget id="calculator">1 ** 2</gadget>
<output>1</output>

<gadget id="calculator">3.14 * 1 * 2 * 10</gadget>
<output>62.8</output>

<result>62.8</result>