input: Write a python function to compare two numbers and print "A is less than B" if the first number is less than the second, otherwise print "A is not less than B".
  assert compare_numbers(3, 5) == "A is less than B"
  assert compare_numbers(10, 5) == "A is not less than B"
  assert compare_numbers(7, 7) == "A is not less than B"
output: def compare_numbers(a, b):
      if a < b:
          return "A is less than B"
      else:
          return "A is not less than B"