If two squares with a side length of 2 cm are put together to form a rectangle, what is the perimeter of the rectangle in cm?
2个边长2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">2 + 2</gadget>
<output>4</output>

<gadget id="calculator">4 + 2</gadget>
<output>6</output>

<gadget id="calculator">6 * 2</gadget>
<output>12</output>

<result>12</result>