The problem with that is that it isn't actually counting the R's.

You'd probably have better luck asking it to write a script for you that returns the number of instances of a letter in a string of text, then getting it to explain to you how to get it running and how it works. You'd get the answer that way, and also then have a script that could count almost any character and text of almost any size.

That's much more complicated, impressive, and useful, imo.