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
6880
6879
6878
6877
6876
6875
6874
6873
6872
6871
6870
6869
6868
6867
6866
6865
6864
6863
6862
6861
6860