There is a rectangular piece of paper with a length of 20 cm and a width of 12 cm. If a square piece of paper is to be cut off, what is the circumference of the remaining piece of paper in centimeters?
有一个长20厘米，宽12厘米的长方形纸片．要在上面裁掉一个以宽为一条边的正方形纸片，剩下纸片的周长是多少厘米？
<gadget id="calculator">20 - 12</gadget>
<output>8</output>

<gadget id="calculator">8 + 12</gadget>
<output>20</output>

<gadget id="calculator">20 * 2</gadget>
<output>40</output>

<result>40</result>