The side length of a cube glass container is 3 decimeters. Pour 18 liters of water into the container, and then put a stone in the water (the stone is completely submerged in the water). At this time, the water depth in the container is measured to be 25 cm. What is the volume in cubic decimeters?
一个正方体玻璃容器的棱长为3分米，向容器中倒人18升水，再在水中放人一块石头(石头完全浸没在水中)，这时量得容器内的水深25厘米，这块石头的体积是多少立方分米？
<gadget id="calculator">3 * 3 * 2.5</gadget>
<output>22.5</output>

<gadget id="calculator">22.5 - 18</gadget>
<output>4.5</output>

<result>4.5</result>