You are asked to write a program that lists all the different words in the input text. In this problem, a word is defined as a consecutive sequence of alphabets, in upper and/or lower case.
Words with only one letter are also to be considered. Furthermore, your program must be CaSe InSeNsItIvE. For example, words like “Apple”, “apple” or “APPLE” must be considered the same.
Several paragraphs of text are given. Multiple lines of texts may appear.
The total charaters will not exceed 2*105
The charater is either an upper or lower case alphabet.
Print the words in alphabetical order and in lower case.
Each word should be sepatated by '\n'.