There are buses No. 19 and No. 21 at the bus station. No. 19 departs every 8 minutes, and No. 21 departs every 5 minutes. If the two buses depart at the same time at a certain time, then the next time At the same time, how many minutes will it take for the train to depart at least.
公交车站有19路和21路公交车，19路每8分钟发一班车，21路每5分钟发一班车，如果这两路车都在某个时间同时发车，那么这两路车下一次同时发车至少要再过多少分钟．
<gadget id="calculator">5 * 8</gadget>
<output>40</output>

<result>40</result>