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
7850
7849
7848
7847
7846
7845
7844
7843
7842
7841
7840
7839
7838
7837
7836
7835
7834
7833
7832
7831
7830