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
8010
8009
8008
8007
8006
8005
8004
8003
8002
8001
8000
7999
7998
7997
7996
7995
7994
7993
7992
7991
7990