Cut a rectangular piece of paper with a length of 36 cm and a width of 20 cm into the same small square piece of paper, what is the longest side length of the cut square piece of paper?
把一个长是36厘米，宽是20厘米的长方形纸张裁成相同的小正方形纸片，裁成的正方形纸片的边长最长是多少？
<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<result>4</result>