input: 
  def convert_integer_sign(x: int) -> int:
      """ Converts a positive integer to negative or vice versa using bitwise NOT operator.
      >>> convert_integer_sign(5)
      -5
      >>> convert_integer_sign(-8)
      8
      """
      if x < 0:
          return ~(x-1)
      else:
          return ~x + 1
  
output:     if x < 0:
          return ~(x - 1)
      else:
          return ~x + 1