long-distance bus station sends a bus to the north line every 20 minutes, and sends a bus to the south line every 25 minutes. If a bus starts to both lines at the same time at a certain time, at least how many minutes will it take to start at the same time.
某长途汽车站向北线每20分钟发一辆汽车，向南线每25分钟发一辆汽车，如果某时刻同时向两线发车，至少要经过多少分钟又同时发车．
<gadget id="calculator">5 * 2 * 2 * 5</gadget>
<output>100</output>

<result>100</result>