What is the minimum length of iron wire needed to make a cuboid frame with a bottom perimeter of 18 cm and a height of 3 cm?
至少需要多长的铁丝，才能做一个底面周长是18厘米，高3厘米的长方体框架呢？
<gadget id="calculator">18 * 2</gadget>
<output>36</output>

<gadget id="calculator">3 * 4</gadget>
<output>12</output>

<gadget id="calculator">36 + 12</gadget>
<output>48</output>

<result>48</result>