Uncle Li made a cuboid birdcage whose length, width, and height are 30 cm, 15 cm, and 20 cm respectively.
李叔叔做一个长、宽、高分别是30厘米、15厘米和20厘米的长方体鸟笼，至少需要多少长的铁丝(不计接口处)．
<gadget id="calculator">30 + 15 + 20</gadget>
<output>65</output>

<gadget id="calculator">65 * 4</gadget>
<output>260</output>

<result>260</result>