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
7770
7769
7768
7767
7766
7765
7764
7763
7762
7761
7760
7759
7758
7757
7756
7755
7754
7753
7752
7751
7750