To see Tanya, Vlad must cross Border Point A (leaving his home region) and Border Point B (entering hers). At each checkpoint, he faces corrupt officers, lost paperwork, 12-hour delays, and the constant threat that his cargo (timber, coal, or frozen fish) will spoil if he is held too long.

And somewhere, between one queue and the next, a ghost in a green truck still waits for his stamp.

: If the problem involves queues, familiarize yourself with basic queueing theory. This might include understanding different types of queues (e.g., FIFO - First In, First Out) and how they can be modeled.