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
4180
4179
4178
4177
4176
4175
4174
4173
4172
4171
4170
4169
4168
4167
4166
4165
4164
4163
4162
4161
4160