D1212121212131323131133132311233132322331333133313123231323221221   >>    D121212121213132313113313231123313232233133313331312323132322122   <<    D1212121212131323131133132311233132322331333133313123231323221223   >>      D1212121212131323131133132311233132322331333133313123231323221222   >>