Cut out the largest square from one end of a rectangular piece of paper with a length of 30 cm. What is the circumference of the remaining piece of paper in centimeters?
从一张长为30厘米的长方形纸片的一端，剪下一个最大的正方形，剩下纸片的周长是多少厘米．
<gadget id="calculator">30 * 2</gadget>
<output>60</output>

<result>60</result>