The length, width, and height of a paper bag are 35cm, 12cm, and 20cm respectively. To make 30 such paper bags, what is the minimum area of paper needed?
一个纸袋的长、宽、高分别是35cm、12cm、20cm，要做这样的纸袋30个，至少需要多大面积的纸？
<gadget id="calculator">700 + 240</gadget>
<output>940</output>

<gadget id="calculator">940 * 2</gadget>
<output>1_880</output>

<gadget id="calculator">420 + 1_880</gadget>
<output>2_300</output>

<gadget id="calculator">2_300 * 30</gadget>
<output>69_000</output>

<result>69_000</result>