In this problem, you are given a paragraph of text in terms of a sequence of lines. Each lines contains a number of words which are sequences of lowercase and uppercase letters and are separated by either blank characters or asterisks. A word is wiped out if for each character in that word, there is no letter or asterisk character in the same position in the next line, or the word appears in the last line of the input. If such a case happens, all occurrences of that word in the text is converted to blanks independent of the corresponding characters in the next line. Note that the asterisks and black characters never disappear. Also, note that the words are considered case-sensitive. Write a program to read a sequence of lines described above and wipe out as many word as it can iteratively.