Given n-1 points, numbered from 2 to n, the edge weight between the two points a and b is lcm(a, b). Please find the minimum spanning tree formed by them.
A minimum spanning tree is a subset of the edges of a connected, edge-weighted undirected graph that connects all the vertices together, without any cycles and with the minimum possible total edge weight. That is, it is a spanning tree whose sum of edge weights is as small as possible.
lcm(a, b) is the smallest positive integer that is divisible by both a and b.