fsa_hash reads lines from the input. Each line contains either one word, or one number. Every word is looked up in specified dictionaries. If the word is found, its number is printed, if not, -1 is printed. Every number is treated as a word number. The word corresponding to that number is printed, or an error message if the word is not present in the dictionary. Note that fsa_hash is only a demo of what the underlying funtions can do.