Three logs with a diameter of 12 centimeters in cross-section are tightly tied side by side with iron wires. How many centimeters of iron wires should be used at least for one round?
把3根横截面的直径都是12厘米的圆木用铁丝紧紧地并排捆在一起，捆一周至少要用多少厘米铁丝？
<gadget id="calculator">3.14 * 12</gadget>
<output>37.68</output>

<gadget id="calculator">4 * 12</gadget>
<output>48</output>

<gadget id="calculator">37.68 + 48</gadget>
<output>85.68</output>

<result>85.68</result>