text: from sys import exit
  
  
  def count(start, end, interval):
      while start < end:
          yield start
          start += interval
  
  
  def main():
      cc = count(1, 1337, 21)
      for c in cc:
          print(c)
  
      return 0
  
  
  if __name__ == '__main__':
      exit(main())
  