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
3970
3969
3968
3967
3966
3965
3964
3963
3962
3961
3960
3959
3958
3957
3956
3955
3954
3953
3952
3951
3950