input: Write a python function to calculate the number of days an employee is free from meetings given a certain number of days and a list of meeting intervals. The function should be titled `days_without_meetings` and should not overlap with the original problem's text.
  
  from typing import List
  
  def days_without_meetings(days: int, meetings: List[List[int]]) -> int:
      """
      Given a positive integer representing the total number of days available for work and a 2D list where each sublist contains two integers indicating the start and end days of a meeting inclusive, return the number of days when the employee is free from any meetings.
  
      Note:
      Meetings may be scheduled on overlapping days.
  
      Examples:
      >>> days = 10, meetings = [[5,7],[1,3],[9,10]]
      2
      >>> days = 5, meetings = [[2,4],[1,3]]
      1
  
      Constraints:
      1 <= days <= 10^9
      1 <= len(meetings) <= 10^5
      meetings[i].length == 2
      1 <= meetings[i][0] <= meetings[i][1] <= days
      """
output: def days_without_meetings(days: int, meetings: List[List[int]]) -> int:
      occupied_days = set()
      for meeting in meetings:
          start, end = meeting
          for day in range(start, end + 1):
              occupied_days.add(day)
      return days - len(occupied_days)