Inbox Manager [Java]

import java.util.*;

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

        Map<String, List<String>> listOfUsers = new TreeMap<>();

        String command = scanner.nextLine();

        while (!"Statistics".equals(command)) {
            String currentCommand = command.split("->")[0];

            if ("Add".equals(currentCommand)) {
                String username = command.split("->")[1];

                if (listOfUsers.containsKey(username)) {
                    System.out.println(String.format("%s is already registered", username));
                } else {
                    listOfUsers.put(username, new ArrayList<>());
                }
            }

            if ("Send".equals(currentCommand)) {
                String username = command.split("->")[1];
                String email = command.split("->")[2];

                listOfUsers.get(username).add(email);
            }

            if ("Delete".equals(currentCommand)) {
                String username = command.split("->")[1];

                if (!listOfUsers.containsKey(username)) {
                    System.out.println(String.format("%s not found!", username));
                } else {
                    listOfUsers.remove(username);
                }
            }

            command = scanner.nextLine();
        }

        System.out.println(String.format("Users count: %d", listOfUsers.size()));

        listOfUsers.forEach((key, value) -> {
            System.out.println(String.format("%s", key));
            for (String sentEmail : value) System.out.println(" - " + sentEmail);
        });
    }
}