cylinder of wood is 20 decimeters high. After being cut into three sections on average, the surface area increases by 12.56 square decimeters. If the original wood is processed into the largest square wood, how many cubic decimeters will it have?
一根圆柱体木料高20分米，平均切成三段后，表面积增加了12.56平方分米，如果把原来的木料加工成最大方木有多少立方分米？
<result>20</result>