D1212121212131323331312323132322331313232233132313223313231313232212121   >>    D121212121213132333131232313232233131323223313231322331323131323221212   <<    D1212121212131323331312323132322331313232233132313223313231313232212123   >>      D1212121212131323331312323132322331313232233132313223313231313232212122   >>