.
                                  missile
                     ­       missilemissile
                           missile  missile
                           missile   missile
                            missile missile
                            missile missile
                            missile missile
                            missile missile
                            missile missile
                            missile missile
                            missile missile
                            missile missile
                            missile missile
                            missile missile
                            missile missile
                 m i s s i l e          m i s s i l e
             missile missile    missile missile
            missile.   missile missile    missile
               missile miss        Ile      missile
                   missile                 missile