Y \ X
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
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
1660
1659
1658
1657
1656
1655
1654
1653
1652
1651
1650
1649
1648
1647
1646
1645
1644
1643
1642
1641
1640