Given a set of distinct positive integers, find the largest subset such that every pair (Si, Sj) of elements in this subset satisfies:
Si % Sj = 0 or Sj % Si = 0.
If there are multiple solutions, return any subset is fine.
Input: [1,2,3] Output: [1,2] (of course, [1,3] will also be ok)
Input: [1,2,4,8] Output: [1,2,4,8]