How many cubes with side lengths of 1 cm are required to form a cube with side lengths of 2 cm.
需要多少个棱长为1厘米的正方体，才能组成一个棱长为2厘米的正方体．
<gadget id="calculator">2 * 2 * 2</gadget>
<output>8</output>

<result>8</result>