If a cuboid is formed from 3 cubes whose sides are 5 decimeters long, the surface area of the cuboid is less than the sum of the surface areas of the 3 cubes by how many square decimeters.
用3个棱长是5分米的正方体合成一个长方体，长方体的表面积比3个正方体的表面积之和少多少平方分米．
<gadget id="calculator">5 * 5 * 4</gadget>
<output>100</output>

<result>100</result>