Letter Count
Write a program contained in a single file named "LetterCount.java" that first
asks the user to enter an integer representing how many words he/she wants to
type, and then uses a 'for' loop to have the user enter exactly that number of
words.  In your loop you should prompt the user to enter each word, using the
word number in your prompt.  After all of the words have been entered, tell the
user the total number of letters used in all of the words.

For example, if the user indicates that he/she wants to enter three words, and
then types "cat", "alligator", and "pumpkin", then your program should report
the number 19 to the user (since 3 + 9 + 7 = 19).  You may assume that the user
will initially enter a positive integer, and that each word entered by the user
will consist only of letters.  All of your output to the user must use complete
sentences (e.g., "A total of 19 letters were used in your word list.").

You may not use any arrays or global variables for this assignment.  For this
program you may, if you wish, put all of your code into the 'main' method.

Advanced Option
Instead of reporting the total number of letters used in the user's words,
report how many different letters were used in all of the user's words.
For example, if the user were to type two words, "computer" and "carrot",
then you would tell the user that a total of nine different letters were
used ("a", "c", "e", "m", "o", "p", "r", "t", "u").  You may use arrays for
this advanced option, and you don't have to report to the user the actual
letters used...only the number of unique letters.