Design a class called NumDays. The class purpose is to store a value that represents a number of work hours and convert it to a number of days. For example, 8 hours would be converted to 1 day, 12 hours would be converted to 1.5 days, and 18 hours would be converted to 2.25 days. The class should have a constructor that accepts a number of hours, as well as member functions for storing and retrieving the hours and days.

The class should also have the following overloaded operators:

+ Addition operator. When two NumDays objects are added together, the overloaded + operator should return the sum of the two objects hours members.

- Subtraction operator. When one NumDays object is subtracted from another, the overloaded - operator should return the difference of the two objects hours members.

++ Prefix and postfix increment operators. These operators should increment the number of hours stored in the object. When, incremented, the number of days should be automatically recalculated.

-- Prefix and postfix decrement operators. These operators should decrement the number of hours stored in the object. When, decremented, the number of days should be automatically recalculated.

Write a program in C++ to demonstrate the NumDays class: create several objects, use their member functions and overloaded operators. Make sure to display (print) the before and after results.