Functional programming in Scala problem:

Output the word (or list of words) that occurs the most times in the text file (irrespective of case i.e. word and Word are treated the same for this purpose). We are only interested in words that contain alphabetic characters [A-Z a-z], so ignore any digits (numbers), punctuation, etc. If there are several words that occur most often with equal frequency then all these words should be printed as a list. Alongside the word(s) you should output the number of occurrences. For example: The word(s) that occur most often are [and, it, the] each with 10 occurrences in the text.