code: def or_list(items: Sequence[str]) -> Optional[str]:
      
      if not items:
          raise ValueError
  
      if len(items) == 1:
          return items[0]
      if len(items) == 2:
          return items[0] + " or " + items[1]
  
      *selected, last_item = items[:MAX_LENGTH]
      return ", ".join(selected) + " or " + last_item
docs: Given [A, B, C] return 'A, B, or C'.