9951번 - Word Extraction 다국어

I am trying to create a dictionary of all the words in common use by my students. To do this, I am planning to feed text from their work, discussion forum entries, and emails through a program that extracts the words.

To make it easy to check if a word has been seen before, I am formatting the text carefully. Firstly I put everything in lower case, then I strip out all punctuation leaving the words separated by single spaces. If the punctuation comes within a word (i.e. there is a letter on either side of it), it is removed. If a "word" consists only of digits, it is ignored. Finally, I sort the words into alphabetical order, removing duplicates.

Input will consist of a number of lines, each line representing a piece of text to be analysed, and terminated by a single #. No line will contain more than 250 characters.

Output will be the qualifying words extracted from the text, one per line, in alphabetical order within each set. Each set of words from a piece of text will be separated from the next set by a blank line.