A packing box is 32 cm long, 20 cm wide, and 14 cm high. If the area of the lower and overlapping parts of the packing box is not counted, how much cardboard is needed at least?
一包装箱长32厘米，宽20厘米，高14厘米，如果不计包装箱低重合部分的面积，至少需要多大的硬纸板？
<gadget id="calculator">32 * 20</gadget>
<output>640</output>

<gadget id="calculator">32 * 14</gadget>
<output>448</output>

<gadget id="calculator">20 * 14</gadget>
<output>280</output>

<gadget id="calculator">640 + 448 + 280</gadget>
<output>1_368</output>

<gadget id="calculator">1_368 * 2</gadget>
<output>2_736</output>

<result>2_736</result>