Three cars A, B, and C are driving in the same direction on the circular road. It takes 12 minutes for A to travel, 18 minutes for B to travel a week, and 36 minutes for C to travel a week. The three cars start from the same starting point, at least How long does it take for the three cars to meet again at the starting point at the same time?
甲、乙、丙三辆汽车在环形马路上同向行驶，甲车行一周要12分钟，乙车行一周要18分钟，丙车行一周要36分钟，三辆汽车从同一起点出发，至少要经过多长时间这三辆汽车才能同时又在起点相遇？
<gadget id="calculator">2 * 2 * 3 * 3</gadget>
<output>36</output>

<result>36</result>