Create a program to input from the keyboard by allowing the user to enter grades as long as they don't enter $999$ to quit. If the grade$$entered is the $10$th grade, the grade is forced to $999$ and the loop ends; otherwise, the user enters another quiz grade.$$

You will need to have two separate $.$cpp files. One to store the main, and the second file will contain a class will contain the methods to process the grades.$$

Use a loop to allow the user to continue to enter grades as long as they don't enter $999$ to quit or the $10$th grade is entered. After the user enters the $10$ grade, the program stops accepting additional grades from the user.

You will need to use an array to store the student's quiz grades. The array can only store $10$ grades. The quiz scores range from $0-100.$ You do not store the $999$ in the array. The $999$ is used to tell the program to stop accepting grades as input from the user.

Compute the average of the quiz grades.

Use decision logic to find out the letter grade of the average based on the following grading scale and print to the console.

A$=90-100$

B$=80-89$

C$=70-79$

D$=60-69$

F$=0-59$