WRITE ME A C++ PROGRAM OF A BILLING SYSTEM WITH A STANDARD CHARGE [on hold]

Here is the question. Its been eating up my head.

Kenya power creates a bill using the following criteria. - There is a standard fee of KES200 monthly -The first 100 units are charged at KES5 per unit, the next 50 units is charged at KES10 per unit. - The next 50 units are charged at KES25 per unit -For units beyond 200 are charged KES15 per unit -Write a program that allows a user to enter the number of units consumed and the program calculates the amount payable.