A, B, and C are friends. They go to the library every 3 days, B once 4 days, and C once every 5 days. One day, the three of them happened to meet in the library. Ask at least how many more days the three of them will meet again in the library?
甲、乙、丙三人是朋友，他们每隔不同天数到图书馆去一次，甲3天去一次，乙4天去一次，丙5天去一次．有一天，他们三人恰好在图书馆相会．问至少再过多少天他们三人又在图书馆相会？
<gadget id="calculator">3 * 4 * 5</gadget>
<output>60</output>

<result>60</result>