The length, width, and height of a cuboid are a meter, b meter, and h meter respectively. If the height increases by 3 meters, how many square meters will the surface area of the new cuboid increase compared to the original one?
一个长方体的长、宽、高分别为a米、b米、h米，如果高增加3米，那么新的长方体表面积比原来增加多少平方米．
<gadget id="calculator">2 * 3</gadget>
<output>6</output>

<result>6</result>