I want to paste a cuboid box, but I forgot the length, width, and height of the box. I just remember that it is made of an 84-decimeter iron wire, and the length, width, and height are all decimeters. How much paper should I use at least to ensure enough?
要糊长方体箱，但忘了箱子的长、宽、高，只记得是用一根84分米的铁丝做成的，而且长、宽、高都是整分米．至少用多少纸才能保证够用？
<gadget id="calculator">1 + 1 + 19</gadget>
<output>21</output>

<gadget id="calculator">21 / 3</gadget>
<output>7</output>

<gadget id="calculator">7 * 7 * 6</gadget>
<output>294</output>

<result>294</result>