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
12520
12519
12518
12517
12516
12515
12514
12513
12512
12511
12510
12509
12508
12507
12506
12505
12504
12503
12502
12501
12500