There is a rectangular box with a length of 40 cm, a width of 20 cm, and a height of 10 cm. Now to wrap this cuboid box with a kind of wrapping paper, how much wrapping paper is needed at least?
有一个长40厘米、宽20厘米、高10厘米的长方体盒子．现要用一种包装纸把这个长方体盒子整个包起来，至少需要多少包装纸？
<gadget id="calculator">40 * 20</gadget>
<output>800</output>

<gadget id="calculator">20 * 10</gadget>
<output>200</output>

<gadget id="calculator">40 * 10</gadget>
<output>400</output>

<gadget id="calculator">800 + 200 + 400</gadget>
<output>1_400</output>

<gadget id="calculator">1_400 * 2</gadget>
<output>2_800</output>

<result>2_800</result>