input: Write a function to convert a positive integer to negative or vice versa using the bitwise NOT operator. If the given number is positive, return its negative equivalent and vice versa.
  assert convert_to_negative(5)==-5
  assert convert_to_negative(-5)==5
  assert convert_to_positive(5)==-5
  assert convert_to_positive(-5)==5
output: def convert_to_negative(n):
      return ~n + 1
  
  def convert_to_positive(n):
      return ~n + 1