input: def convert_to_negative(x: int) -> int:
      """Convert a positive integer to negative using bitwise NOT operator.
      >>> convert_to_negative(5)
      -5
      >>> convert_to_negative(0)
      0
      """
      return ~x + 1
  
  def convert_to_positive(x: int) -> int:
      """Convert a negative integer to positive using bitwise NOT operator.
      >>> convert_to_positive(-5)
      5
      >>> convert_to_positive(0)
      0
      """
      return ~(x - 1)
output:     if x >= 0:
          return x
      return ~x + 1