A rectangular vegetable field is 12 meters wide, and its length is 4 meters less than twice its width. What is the perimeter of this rectangle in meters?
一块长方形菜地，宽12米，长比宽2倍的少4米，这个长方形的周长是多少米？
<gadget id="calculator">12 * 2</gadget>
<output>24</output>

<gadget id="calculator">24 - 4</gadget>
<output>20</output>

<gadget id="calculator">20 + 12</gadget>
<output>32</output>

<gadget id="calculator">32 * 2</gadget>
<output>64</output>

<result>64</result>