public void input() {
    Scanner keyboard = new Scanner(System.in);
    System.out.print("Move (l/r/u/d): ");
    String name = keyboard.nextLine();

    if(name.equals("l")) {
        move(-1,0);
    }
    else if(name.equals("r")) {
        move(1,0);
    }
    else if(name.equals("u")) {
        move(0,-1);
    }
    else if(name.equals("d")) {
        move(0,1);
    }
    else {
        System.out.println("Invalid move");
    }
}