Make a pair of rectangular parallelepiped tin boxes without a cover, with a length of 18 decimeters, a width of 12 decimeters, and a height of 10 decimeters. What is the minimum area required for the iron sheet?
用铁皮做一对无盖的长方体铁皮箱，箱长18分米，宽12分米，高10分米．至少需要铁皮的面积是多少？
<gadget id="calculator">18 * 12</gadget>
<output>216</output>

<gadget id="calculator">18 * 10 * 2</gadget>
<output>360</output>

<gadget id="calculator">12 * 10 * 2</gadget>
<output>240</output>

<gadget id="calculator">216 + 360 + 240</gadget>
<output>816</output>

<result>816</result>