Cut out the largest square from a rectangular iron sheet with a length of 17 cm and a width of 5 cm. What is the perimeter of the square iron sheet in cm?
从一个长17厘米，宽5厘米的长方形铁皮上剪下一个最大正方形，正方形的铁皮周长是多少厘米．
<gadget id="calculator">5 * 4</gadget>
<output>20</output>

<result>20</result>