There are two iron wires, each of which is 30 cm long. If the two iron wires are joined together, the joint is 2 cm long. What is the total length of the two iron wires when they are joined together?
有两根铁丝每根铁丝30厘米，把两根铁丝接在一起，接头有2厘米，请问两根铁丝接在一起总共长多少厘米？
<gadget id="calculator">30 - 2</gadget>
<output>28</output>

<gadget id="calculator">30 + 28</gadget>
<output>58</output>

<result>58</result>