Y \ X
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
3960
3959
3958
3957
3956
3955
3954
3953
3952
3951
3950
3949
3948
3947
3946
3945
3944
3943
3942
3941
3940