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
7510
7509
7508
7507
7506
7505
7504
7503
7502
7501
7500
7499
7498
7497
7496
7495
7494
7493
7492
7491
7490