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
1540
1539
1538
1537
1536
1535
1534
1533
1532
1531
1530
1529
1528
1527
1526
1525
1524
1523
1522
1521
1520