Write a C$++$ program whose main function is merely a collection of variable declarations and function calls. This program reads in text and outputs the letters, together with their counts. You are not allowed to use global variables. All information must be passed in and out of the functions. You will use an array to keep a count for all of the letters. Both the input file and output file must be given by the user. Your program will be broken up into $4$ functions, in four different files. Because they are in different files, you are being forced to not use global variables. One of the files is given to you $($main$.$cpp$).$