If two squares with side lengths of 4 cm are put together to form a rectangle, what is the perimeter of the rectangle in cm?
把两个边长是4厘米的正方形拼成一个长方形，这个长方形的周长是多少厘米．
<gadget id="calculator">4 + 4</gadget>
<output>8</output>

<gadget id="calculator">8 + 4</gadget>
<output>12</output>

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

<result>24</result>