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, return the negative equivalent and if it is a negative integer, return the positive equivalent.
  
  assert convert_to_negative(5)== -5
  assert convert_to_positive(-5)==5
  assert convert_to_negative(0)==0
  assert convert_to_positive(-10)==10
  assert convert_to_negative(12)==-12
output: def convert_to_negative(n):
      return ~n + 1
  
  def convert_to_positive(n):
      return ~n + 1