Write a program that finds the grade corresponding to the average mark. The program uses a function called average(int) that takes an integer representing the number of marks, then the function reads the marks and returns their average. Write another function called grade(double) that takes a double representing the average of marks, and returns a characher which is the average grade. Write a main function which calls the two functions average(int) and grade(double) and prints the grade of the marks eantng the ave fmar, arogeint) and gruble) and prinis Sample input/output: nter the number of marks: 5 nter a mark: 63 Enter a mark: 77 ter a mark: 81 nter a mark 94 nter a mark: 52 The grade of the 5 marks is: C