Students go to the community to do good deeds. If there are 6 people in each group, the number can be divided just right; if there are 9 people in each group, the number can be divided just right. So how many students go to the community to do good deeds?
同学们去社区做好事，如果每组6人，人数刚好分完；如果每组9人，也恰好能分完．那么去社区做好事的同学至少多少人．
<gadget id="calculator">2 * 3 * 3</gadget>
<output>18</output>

<result>18</result>