If a cuboid is cut into a small cuboid and a cube, the surface area increases by 18 square meters. What is the surface area of the cube?
把一个长方体截成一个小长方体和正方体，表面积增加了18平方米，正方体的表面积是多少？
<gadget id="calculator">18 / 2</gadget>
<output>9</output>

<gadget id="calculator">9 * 6</gadget>
<output>54</output>

<result>54</result>