There is a propaganda wall with a length of 32 decimeters and a width of 28 decimeters. The wall is just covered with square tiles. What is the maximum side length of the tiles?
有一面宣传墙长是32分米，宽是28分米，用正方形瓷砖正好把这面墙贴满，瓷砖的边长最大是多少分米．
<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<result>4</result>