A cylinder of wood, if split in half along the diameter of the base, increases the surface area by 120 square centimeters. If the middle is cut into two small cylinders, the surface area will increase by 157 square centimeters. What is the volume of the original cylindrical log?
一个圆柱形木料，如果沿着底面直径劈成两半，表面积增加120平方厘米．如果拦腰截成两个小圆柱，表面积则增加157平方厘米．原圆柱形木料的体积是多少？
<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

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

<gadget id="calculator">120 / 2 / 10</gadget>
<output>6</output>

<gadget id="calculator">3.14 * 25 * 6</gadget>
<output>471</output>

<result>471</result>