SoftUni Parking

import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Scanner;

public class SoftUniParking {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        Map<String, String> usersLicensePlate = new LinkedHashMap<>();

        int line = Integer.parseInt(scanner.nextLine());

        for (int i = 0; i < line; i++) {
            String[] tokens = scanner.nextLine().split("\\s+");
            String register = tokens[0];
            String user = tokens[1];

            if (register.equals("register")) {
                String licensePlate = tokens[2];
                if (usersLicensePlate.containsKey(user)) {
                    System.out.printf("ERROR: already registered with plate number %s%n", licensePlate);

                } else {
                    usersLicensePlate.put(user, licensePlate);
                    System.out.printf("%s registered %s successfully%n", user, licensePlate);
                }
            }

            if (register.equals("unregister")) {
                if (!usersLicensePlate.containsKey(user)) {
                    System.out.printf("ERROR: user %s not found%n", user);
                } else {
                    usersLicensePlate.remove(user);
                    System.out.printf("%s unregistered successfully%n", user);
                }
            }
        }

        usersLicensePlate
                .forEach((k, v) -> System.out.printf("%s => %s%n", k, v));
    }
}