D1212121212131323331323231323132312323132322331311331323132333132322121   >>    D121212121213132333132323132313231232313232233131133132313233313232212   <<    D1212121212131323331323231323132312323132322331311331323132333132322123   >>      D1212121212131323331323231323132312323132322331311331323132333132322122   >>