Three logs with a cross-sectional diameter of 10 cm are tightly bound together with wire. At least how many centimeters of iron wire should be used to tie a week.
把3根横截面直径是10厘米的圆木用铁丝紧紧地捆在一起．捆一周至少用铁丝多少厘米．
<gadget id="calculator">4 * 10</gadget>
<output>40</output>

<gadget id="calculator">314 + 40</gadget>
<output>354</output>

<result>354</result>