Cipher Lab give you some practice, The purpose of this short assignment is to using e is a prog ciphe c, which will and You will number of places, Thus, if the shift a message by shifting each letter some Like this: then A becomes becomes D, and so on. A B C D E F G H I J Surprisingly, you can do this by doing with characters, but letter contains C that the is a using a result 67, which the value 'A', then 'A' 2 gives the integer you can turn back into a character by saying (char) (letter 2), giving the Unfortunately, (char) ('Z' 2) does not give you the letter 'B. (you can why from the picture above). But if you realize you went past z you can subtract 26 (so the result is "z' 2 26, or Z 24), and this will give This also means that if you encode a message with a shift of n, you can decode it with another shift of 26 n. Your program should first call a function, processFile which reads a message from a file (congress .txt) into a very large character array.The function should convert all of the letters into uppercase characters. You may discard all the punctuation marks, digits, blanks, and anything else from the input Your program should then accept the amount to shift as an input to a function, cipher 0. The input parameter should be 13, although for your testing purposes, you can simplify things by using a shift of 1. Your function should encode each letter by shifting it the correct amount, and put the encoded letters into null-terminated array of characters. Finally, you should create a outputcode which outputs final encoded in blocks of the shorter than five blocks, five letters, ten blocks per line. The last line may and the last block may be shorter than five letters Focus on Fundamentals of Programming with C Page 360