The radius of the bottom of a cylindrical container filled with water is 5 cm. Take out a stone submerged in the water, and the water level drops by 2 cm. What is the volume of the stone in cubic centimeters?
装有水的圆柱形容器底面半径5厘米，将浸没在水中的石块取出，水面下降2厘米，石块的体积是多少立方厘米．
<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<gadget id="calculator">3.14 * 25 * 2</gadget>
<output>157</output>

<result>157</result>