Suppose that we are working for an online service that provides a bulletin board for its users. We would like to give our users the option of filtering out profanity. Suppose that we consider the words cat, dog, and llama to be profane. Write a program that reads a string from the keyboard and tests whether the string contains one of our profane words. Your program should find words like cAt that differ only in case. Option: As an extra challenge, have your program reject only lines that contain a profane word exactly. For example, Dogmatic concatenation is a small category should not be considered profane.