What is the maximum surface area of this cuboid in square centimeters if four small cubes with side lengths of 1 cm are built into a cuboid?
把边长是1厘米的四个小正方体搭成一个长方体，这个长方体的最大表面积是多少平方厘米
<gadget id="calculator">1 * 4</gadget>
<output>4</output>

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

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

<gadget id="calculator">4 + 4 + 1</gadget>
<output>9</output>

<gadget id="calculator">9 * 2</gadget>
<output>18</output>

<result>18</result>