If two small cubes with side lengths of 3 cm are used to form a large cuboid, the surface area is reduced by how many square centimeters.
用两个棱长3厘米的小正方体拼成一个大长方体，表面积减少了多少平方厘米．
<gadget id="calculator">3 * 3 * 2</gadget>
<output>18</output>

<result>18</result>