Programming project involves writing a program that computes the average salary for a collection of employees of different types. This program consists of four classes. The first class is the Employee class, which contains the employee's name and monthly salary, which is specified in whole dollars. It should have two methods:
1. A constructor that allows the name and monthly salary to be initialized.
2. A method named annualSalary that returns the salary for a whole year.
The Employee class has two subclasses. The first is Salesman. It has an additional instance variable that contains the annual sales in whole dollars for that salesman. It should have the same two methods:
1. A constructor that allows the name, monthly salary and annual sales to be initialized.
2. An overridden method annualSalary that returns the salary for a whole year. The salary for a salesman consists of the base salary computed from the monthly salary plus a commission. The commission is computed as 2% of that salesman's annual sales. The maximum commission a salesman can earn is $20,000.