There are three squares with a perimeter of 12 centimeters that are put together to form a rectangle. What is the perimeter of the rectangle in centimeters?
有三个周长都为12厘米的正方形，拼成一个长方形，长方形的周长是多少厘米？
<gadget id="calculator">12 / 4</gadget>
<output>3</output>

<gadget id="calculator">3 * 3</gadget>
<output>9</output>

<gadget id="calculator">9 + 3</gadget>
<output>12</output>

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

<result>24</result>