input: Write a function to convert a positive integer to negative or vice versa using the bitwise NOT operator. If the input is a positive integer, convert it to a negative integer, and if the input is a negative integer, convert it to a positive integer. 
  def convert_to_negative(x): 
      return ~x + 1 
    
  def convert_to_positive(x): 
      return ~(x-1)
  
  assert convert_to_negative(5) == -5
  assert convert_to_negative(-3) == -3
  assert convert_to_positive(-7) == 7
  assert convert_to_positive(9) == 9
output: def convert_to_negative(x): 
      return ~x + 1 
    
  def convert_to_positive(x): 
      return ~(x-1)