If three "Dictionaries" with a length of 20cm, a width of 15cm, and a thickness of 6cm are packed together according to the plan of saving wrapping paper, how many square centimeters will the surface area of these three cuboid "Dictionaries" be reduced?
把3本长20cm、宽15cm、厚6cm的《字典》按照最节约包装纸的方案包在一起，这3本长方体《字典》的表面积会减少多少平方厘米．
<gadget id="calculator">20 * 15 * 4</gadget>
<output>1_200</output>

<result>1_200</result>