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
7970
7969
7968
7967
7966
7965
7964
7963
7962
7961
7960
7959
7958
7957
7956
7955
7954
7953
7952
7951
7950