A log with a length of 2 meters is sawn into 3 pieces, and the surface area increases by 12.56 square decimeters. What is its original volume in cubic decimeters?
一个长2米的圆木，锯成3段，表面积增加了12.56平方分米，它原来的体积是多少立方分米？
<gadget id="calculator">12.56 / 4</gadget>
<output>3.14</output>

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

<result>62.8</result>