C++ File I/O. Sentence Filter. Write a program that asks the user for two file names. The first file will be opened for input and the second file will be opened for output. It will be assumed that the first filecontains sentences that end with a period. The program will read the contents of the first file and change all the letters to lowercase except the first letter of each sentence, which should be made uppercase. The revised contents should be stored in the second file.