If two cuboids with a length of 20 cm, a width of 15 cm, and a height of 6 cm are put together to form a large cuboid, the surface area will be reduced by at least how many square centimeters.
将两个长20厘米，宽15厘米，高6厘米的长方体拼成一个大长方体，表面积至少减少多少平方厘米．
<gadget id="calculator">15 * 6 * 2</gadget>
<output>180</output>

<result>180</result>