Y \ X
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
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
3960
3959
3958
3957
3956
3955
3954
3953
3952
3951
3950
3949
3948
3947
3946
3945
3944
3943
3942
3941
3940