Aunt Li watered the rose and Clivia at the same time today. The rose was watered every 14 days, and the Clivia was watered every 21 days. At least how many days later should I water these two kinds of flowers at the same time?
李阿姨今天给月季和君子兰同时浇水，月季每14天浇一次水，君子兰每21天浇一次水，至少多少天以后给这两种花同时浇水？
<gadget id="calculator">2 * 3 * 7</gadget>
<output>42</output>

<result>42</result>