def recursive_min(nxs):
    """
      Find the maximum in a recursive structure of lists
      within other lists.
      Precondition: No lists or sublists are empty.
    """
    smallest = None
    first_time = True
    for e in nxs:
        if type(e) == type([]):
            val = recursive_min(e)
        else:
            val = e

        if first_time or val < smallest:
            smallest = val
            first_time = False
    return smallest