There is water 5 cm deep in a cuboid tank with a length of 16 cm, a width of 8 cm, and a height of 9 cm. Now put a stone into the water tank. At this time, the water level is 7 cm from the bottom of the tank. What is the minimum volume of the stone?
在长为16厘米、宽为8厘米、高为9厘米的长方体水箱中有5厘米深的水．现在往水箱里放入一块石头，这时水平面离箱底7厘米，则石头的体积至少是多少？
<gadget id="calculator">7 - 5</gadget>
<output>2</output>

<gadget id="calculator">16 * 8 * 2</gadget>
<output>256</output>

<result>256</result>