Define a class that represents Rational Numbers (fractions). 
Your class should protect its data members against uncontrolled access,
and provide suitable methods for all permissible operations.

Define the standard arithmetical and comparison operators. 
Make sure that the result of every operation is properly normalised 
(for example, 1/2 multiplied by 2/3 should give 1/3, not 2/6).

Write a simple interactive calculator application around your definitions.
It should allow the user to enter operations on fractions in a convenient 
form, and display the results.

This assignment must run under the Unix system.


Here is a sample of what a run might look like. You do not
have to follow this example.

  = 1/2

   answer 1/2

  * 2/3

   answer 1/3

  * 12/1

   answer 4/1

  = 12/14

   answer 6/7

  + 1/5

   answer 37/25

and so on...