Thank you for the reply! The text file contains one word per line, and no words in the file repeated. You could basically think of the text file as a dictionary of standard English words. Ideally the user would be able to easily supply any letter pair each execution. I figured it would be easier for me just to see some code that will do the trick for the R/S pairing, and then I assumed it would be easy enough matter to add some lines that would allow the user to input any pair whatsoever.