A self-checkout scans a list of item names. The menu is a dictionary of item name to price. Some scanned items might not be on the menu.
Write checkout(menu, scanned) that returns a list of two things: [total, unknown].
total is the price of every scanned item that is on the menu. Count repeats every time.unknown is a list of the scanned names that are not on the menu. Each one appears only once, in the order it was first scanned.[0, []].