If two rectangles with a length of 4 cm and a width of 3 cm are put together to form a large rectangle, what is the shortest perimeter of this rectangle in cm?
用两个长是4厘米，宽3厘米的长方形拼成一个大长方形，这个长方形的周长最短是多少厘米．
<gadget id="calculator">3 + 3</gadget>
<output>6</output>

<gadget id="calculator">6 + 4</gadget>
<output>10</output>

<gadget id="calculator">10 * 2</gadget>
<output>20</output>

<result>20</result>