Cut out the largest square from a rectangular piece of paper with a length of 25 decimeters and a width of 15 decimeters. What is the perimeter of this square in decimeters?
在一个长25分米，宽15分米的长方形纸片上剪下一个最大的正方形，这个正方形的周长是多少分米．
<gadget id="calculator">15 * 4</gadget>
<output>60</output>

<result>60</result>