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
9880
9879
9878
9877
9876
9875
9874
9873
9872
9871
9870
9869
9868
9867
9866
9865
9864
9863
9862
9861
9860