D1212121212131323331312323132322331313232233132313223313331312312312121   >>    D121212121213132333131232313232233131323223313231322331333131231231212   <<    D1212121212131323331312323132322331313232233132313223313331312312312123   >>      D1212121212131323331312323132322331313232233132313223313331312312312122   >>