If a cuboid becomes a cube if its height increases by 2cm, and its surface area increases by 24cm**2, what is the surface area of this cuboid?
如果一个长方体，如果它的高增加2cm就成一个正方体，而且表面积增加24cm**2，原来这个长方体的表面积是多少．
<gadget id="calculator">24 / 4</gadget>
<output>6</output>

<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">3 * 3 * 2</gadget>
<output>18</output>

<gadget id="calculator">3 * 1 * 4</gadget>
<output>12</output>

<gadget id="calculator">18 + 12</gadget>
<output>30</output>

<result>30</result>