A stone is placed in a cylindrical bucket with a bottom radius of 5 decimeters and a water depth of 4 decimeters, and is completely submerged in the water. The water level rises by 2 decimeters. What is the volume of the stone in cubic decimeters?
在一个底面半径5分米，水深4分米的圆柱形水桶内放入一个石块，并完全浸没在水中，水面上升了2分米，这个石块的体积是多少立方分米？
<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

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

<result>157</result>