Nerd’s Booksellers has a book club

Nerd’s Booksellers has a book club that awards points to its customers based on the number of points of books purchased each month. The points are awarded as follows:

If a customer purchases 0 books, he/she earns 0 points
If a customer purchases 1 books, he/she earns 5 points
If a customer purchases 2 books, he/she earns 15 points
If a customer purchases 3 books, he/she earns 30 points
If a customer purchases 4 books or more, he/she earns 60 points

Write a program that asks the user to enter the number of books that he/she has purchased this month and then display the number of points awarded.