Parking Lot Manager

You are given a parking lot system that simulates vehicle entries and exits. The parking lot has a fixed capacity, and vehicles can enter if there is available space and exit at any time. Additionally, you need to support a command that reports the number of available parking spaces.

Implement a class ParkingLot with the following methods:

• enter(license_plate): Inserts the vehicle into the parking lot if a vehicle with the same license plate is not already present and if there is space available.
• exit(license_plate): Removes the vehicle with the given license plate from the parking lot.
• available(): Returns the number of spaces left, which is given by $$\text{available spaces} = \text{capacity} - \text{number of vehicles}.$$

You are also required to implement a function manage_parking_lot that processes a series of commands from the standard input and outputs the result of each "available" command.

inputFormat

The input begins with an integer N representing the capacity of the parking lot. Each subsequent line contains a command, one per line. The available commands are:

• enter <license_plate> : Attempt to park a vehicle with the given license plate.
• exit <license_plate> : Remove the vehicle with the given license plate from the parking lot.
• available : Print the number of available parking spaces.

The command input terminates when a line containing only '#' is encountered.

outputFormat

For each 'available' command in the input, output the number of available parking spaces. Each result should be printed on a new line.## sample

5
enter ABC123
enter XYZ999
enter LMN456
available
exit ABC123
available
#

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