How many square decimeters will the surface area be reduced by putting together three cubes whose sides are 10 decimeters long to form a cuboid?
把3个棱长为10分米的正方体拼成一个长方体，表面积会减少多少平方分米
<gadget id="calculator">10 * 10</gadget>
<output>100</output>

<gadget id="calculator">100 * 4</gadget>
<output>400</output>

<result>400</result>