A rectangle with a length of 30 cm and a width of 24 cm is exactly divided into several equal squares without any residue. What is the longest side length of this square in cm?
将一个长30厘米、宽24厘米的长方形恰好分割成若干个相等的正方形而没有剩余，这个正方形的边长最长是多少厘米．
<gadget id="calculator">2 * 3</gadget>
<output>6</output>

<result>6</result>