In this exercise, you will modify the program that you created in Chapter 6’s Lab 6-2. If necessary, create a new project named Intermediate21 Project, and save it in the Cpp8\Chap09 folder. Copy the instructions from the Lab6-2.cpp file (which is contained in either the Cpp8\Chap06\Lab6-2 Project folder or the Cpp8\Chap06 folder) into a source file named Intermediate21.cpp. (Alternatively, you can enter the instructions from Figure 6-29 into the Intermediate21.cpp file.) Change the filename in the first comment. Modify the program so that it uses two value-returning functions: one to calculate and return the price of a medium pizza and the other to calculate and return the price of a large pizza. In addition to the $2 coupon on the purchase of a large pizza, Sophia is now e-mailing customers a $1 coupon on the purchase of a medium pizza. Test the program appropriately.