This is an example of using args from main(String[] args) method.     WHAT THIS EXAMPLE DO ?   * It will take arguments and each argument is a path to file.    * Each file can have any number of lines from 1 to N.   * Each line can contain only one integer.   * All of the numbers from all of the files should be added to the final result.   * The result is just one number and it will be displayed usingS System.out.println() method