If a square with a side length of 1 cm is cut from the four corners of a square with a side length of 3 decimeters, what is the perimeter of the remaining figure?
边长3分米的正方形的四角各剪去一个边长1厘米的正方形，剩下的图形的周长是多少分米．
<gadget id="calculator">3 * 4</gadget>
<output>12</output>

<result>12</result>