input: Write a function to calculate the absolute difference between two given numbers. If the given numbers are A and B, it should return the absolute value of the difference between A and B.
  assert absolute_difference(9, 5)==4
  assert absolute_difference(-9, 5)==14
  assert absolute_difference(0, 0)==0
  assert absolute_difference(3, -3)==6
  assert absolute_difference(-9, -5)==4
output: def absolute_difference(A, B):
      return abs(A - B)