An ice cream shop provides ice cream in 20 flavors. It has a single queue. There are two types of events happening in order.
• A number of customers arrive at the shop. They will be in the queue. Each customer is a member and has a unique integer ID. Each customer also specifies the flavor to order (as a number from 1 to 20).
• The first customer in the queue is served. This type of events only happens when there is at least one customer in the queue.
Write a program that simulate the ice cream queue.