(Calculating Total Sales) A mail order house sells five different products whose retail prices are: product 1 — 2.98, product2—4.50, product 3—9.98, product4—4.49 and product 5—$6.87. Write a program that reads a series of pairs of numbers as follows:
a) product number b) quantity sold
Your program should use a switch statement to determine the retail price for each product. Your program should calculate and display the total retail value of all products sold. Use a sentinel-controlled loop to determine when the program should stop looping and display the final results.

The input consists of n (0<n<100) lines.
Each line consists of the product number(ranges from 1 to 5), the quantity sold(ranges from 1 to 100).
The last line of input consists of Int(-1).

The decimal precision of output is 2.