The length of the rectangle is 50cm. After cutting off the largest square, a rectangle remains. What is the perimeter of the rectangle?
长方形的长是50cm，截去一个最大的正方形后，余下一个长方形，这个长方形的周长是多少．
<gadget id="calculator">50 * 2</gadget>
<output>100</output>

<result>100</result>