Weld a cuboid frame with a length of 15cm, a width of 12cm, and a height of 8cm, at least how many centimeters of steel bars are needed.
焊接一个长15cm，宽12cm，高8cm的长方体框架，至少要多少cm长的钢筋．
<gadget id="calculator">15 + 12 + 8</gadget>
<output>35</output>

<gadget id="calculator">35 * 4</gadget>
<output>140</output>

<result>140</result>