A wall is 66dm long and 30dm wide. Square tiles are used to cover the wall. What is the maximum side length of such tiles?
一面墙长为66dm，宽为30dm，用正方形瓷砖正好把这面墙贴满，这样的瓷砖的边长最大是多少分米？
<gadget id="calculator">2 * 3</gadget>
<output>6</output>

<result>6</result>