Y \ X
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
8900
8899
8898
8897
8896
8895
8894
8893
8892
8891
8890
8889
8888
8887
8886
8885
8884
8883
8882
8881
8880