A cuboid container, the bottom of which is a square with a side length of 40 cm, put 8 iron cubes with a side length of 5 cm into the container, and pour 15 liters of water into it to fill it up. Find the depth of the container.
一只长方体容器，底面是边长为40厘米的正方形，在容器中放入8个棱长为5厘米的正方体铁块，再倒入15升水后正好装满，求容器的深度．
<gadget id="calculator">15 * 1_000</gadget>
<output>15_000</output>

<gadget id="calculator">5 * 5 * 5 * 8</gadget>
<output>1_000</output>

<gadget id="calculator">15_000 + 1_000</gadget>
<output>16_000</output>

<gadget id="calculator">40 * 40</gadget>
<output>1_600</output>

<gadget id="calculator">16_000 / 1_600</gadget>
<output>10</output>

<result>10</result>