After an iron wire forms a rectangle with a length of 8 decimeters and a width of 4 decimeters, there is still 6 decimeters left. How many decimeters was the original length of this iron wire?
一根铁丝围成一个长8分米、宽4分米的长方形后，还剩6分米，这根铁丝原来长多少分米？
<gadget id="calculator">8 + 4</gadget>
<output>12</output>

<gadget id="calculator">12 * 2</gadget>
<output>24</output>

<gadget id="calculator">24 + 6</gadget>
<output>30</output>

<result>30</result>