use SI schema

SI schema contains customers that have bought one or more vehicles. They can be classified using the following criteria:

1. Customers that have bought only one car (one-time buyer)
2. Customer that have bought two cars (two-time buyer)
3. Customers that have bought more than two cars (frequent buyer)

Using a SINGLE SELECT statement, display a list of customers with their names and what type of buyer they are for all those customers that have bought Mercedes car makes.