SoftuniParking

import java.lang.reflect.Array;
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);
        int n = Integer.parseInt(scanner.nextLine());

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

        for (int i = 1; i <= n; i++) {
            String[] input = scanner.nextLine().split(" ");
            if (input[0].equals("register")) {
                if (!registered.containsKey(input[1])) {
                    registered.put(input[1], input[2]);
                    System.out.printf("%s registered %s successfully%n", input[1], input[2]);
                } else {
                    System.out.printf("ERROR: already registered with plate number %s%n", registered.get(input[1]));
                }
            }
            if (input[0].equals("unregister")) {
                if (registered.containsKey(input[1])) {
                    registered.remove(input[1]);
                    System.out.printf("%s unregistered successfully%n", input[1]);
                } else {
                    System.out.printf("ERROR: user %s not found%n", input[1]);
                }
            }
        }
        for (Map.Entry<String, String> entry : registered.entrySet()) {
            System.out.printf("%s => %s%n", entry.getKey(), entry.getValue());
        }
    }
}