input: Write a function to print the absolute difference between two given numbers. If both numbers are provided then print the absolute difference else print "Invalid Input". If the two numbers are equal then print 0.
  
  def absolute_difference(A=None, B=None):
      if A is None or B is None:
          return "Invalid Input"
      return abs(A - B) if A != B else 0
  
  assert absolute_difference(9, 5) == 4
  assert absolute_difference(5, 9) == 4
  assert absolute_difference(3, 3) == 0
  assert absolute_difference() == "Invalid Input"
  assert absolute_difference(0, 0) == 0
  assert absolute_difference(10, -10) == 20
output: def absolute_difference(A=None, B=None):
      if A is None or B is None:
          return "Invalid Input"
      return abs(A - B) if A != B else 0