Mathematica solution using $PreRead input preprocessing

This solution uses [`$PreRead`](http://reference.wolfram.com/language/ref/$PreRead.html) which "is applied to the text or box form of every input expression before it is fed to the Wolfram Language" to preprocess input before execution.

Note that this solution must be run like a notebook from the Mathematica GUI. It cannot be run with MathematicaScript or similar. This is because `$PreRead` only applies to input processing of notebook cells.

The replacements and patterns I'm using could possibly be simplified.

I believe this satisfies the rules of the challenge.