Written in C#

Emulate a simple long-distance bus service reservation system. We are dealing with a handful of routes each with a number of daily running buses, each with a specified number of seats. Each customer that buys a ticket will get an assigned seat.

Invalid reservation will result in an exception. Here is a possible list (you might want to come up with a hierarchy of these exceptions): counter is closed, seats are not available, service is cancelled, insufficient funds to purchase, payment gateway is not responding.

No other details mentioned name of routes can be anything.