Python Classwork: Subtraction
    Write a Python program named "Subtraction.py" that has the user
    enter two integers.  Then have your program subtract the smaller
    number from the larger number (larger minus smaller).  Note that
    the user can enter the two integers in any order, so it is up to
    your program to determine which number is larger.  If both numbers
    are the same, then your program should not subtract the numbers,
    but should instead tell the user that the two numbers are the same,
    and then end.

    Your program's output must be formatted exactly like the example
    output shown below.  You do not need to perform error trapping
    for the user input, and you may put all of your code into the
    main area of the program (that is, you are not required to create
    separate functions).  This program should not import or use any
    external functions.


    Example Program Run #1
    ----------------------
    Enter an integer:  42
    Enter another integer:  13

    The difference of your two numbers (42 minus 13) is 29.


    Example Program Run #2
    ----------------------
    Enter an integer:  37
    Enter another integer:  55

    The difference of your two numbers (55 minus 37) is 18.


    Example Program Run #3
    ----------------------
    Enter an integer:  85
    Enter another integer:  85

    The two numbers that you entered are the same.  Goodbye.


  ADVANCED OPTION #1
    In addition to displaying the difference of the two integers, also
    compute and display the sum, product, and quotient of the two
    numbers.  For the quotient, divide the smaller number into the
    larger number, unless the smaller number is zero, in which case
    display a message indicating that division by zero is not allowed.

  ADVANCED OPTION #2
    This advanced option may be may be added into your program along
    with, or instead of, the other advanced options.  Find and display
    both the arithmetic mean (average) and geometric mean of the two
    integers entered by the user.

  ADVANCED OPTION #3
    This advanced option may be may be added into your program along
    with, or instead of, the other advanced options.  Compute and
    display both the greatest common factor and least common multiple
    of the two user-entered integers.