Tie two iron hoops around the outside of a round wooden barrel. The diameter of the wooden barrel is 50 centimeters, and the iron hoop needs 6 centimeters of wire at the joint. How many centimeters of iron wire are needed to bind these two iron hoops?
在一个圆形木桶的外面捆两条铁箍．木桶的直径是50厘米，铁箍连接处需要铁丝6厘米．捆这个两条铁箍共需要多少厘米的铁丝？
<gadget id="calculator">3.14 * 50</gadget>
<output>157</output>

<gadget id="calculator">157 + 6</gadget>
<output>163</output>

<gadget id="calculator">163 * 2</gadget>
<output>326</output>

<result>326</result>