Provide a Python program that uses a while loop and prompts the user for a series of inputs. You should use a sentinel value to signal when the loop should terminate. Calculate and display the sum of the user inputs.

Some examples that you might use are the following:

• Total number of miles traveled on a road trip.
• Total cost of groceries in a month.
• Total number of accidents in a year.

Include comments in your code program that describe what the program does.