Master Huang needs to make a cuboid chimney with a length of 15 centimeters, a width of 10 centimeters and a height of 200 centimeters. How many square centimeters of iron sheets are needed at least?
黄师傅要做一个长15厘米，宽10厘米，高200厘米的长方体烟囱，至少需要多少平方厘米的铁皮？
<gadget id="calculator">15 + 10</gadget>
<output>25</output>

<gadget id="calculator">25 * 2 * 200</gadget>
<output>10_000</output>

<result>10_000</result>