input: Write a function to print the absolute difference between two given numbers. If the given numbers are A and B, return the absolute difference between A and B.
  assert absolute_difference(9, 5)==4
  assert absolute_difference(-3, 8)==11
  assert absolute_difference(-5, -7)==2
  assert absolute_difference(0, -10)==10
  assert absolute_difference(12, 12)==0
output: def absolute_difference(A, B):
      return abs(A - B)