def merge(left,right):
  S=DirectedList()
  S_pos=S.first()
  while not left.isempty() and not right.isempty():
    if left.inspect(left.first()) <= right.inspect(right.first()):
      S.insert(S_pos,left.inspect(left.first()))   #ska lägga in elementet på sista plats
      S_pos=S.next(S_pos)
      left.remove(left.first())

    else:
      S.insert(S_pos,right.inspect(right.first()))  #samma
      S_pos=S.next(S_pos)
      right.remove(right.first())

  while not left.isempty():
    S.insert(S_pos,left.inspect(left.first()))    #samma
    S_pos=S.next(S_pos)
    left.remove(left.first())

  while not right.isempty():
    S.insert(S_pos,right.inspect(right.first()))  #samma
    S_pos=S.next(S_pos)
    right.remove(right.first())

  return S