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
4500
4499
4498
4497
4496
4495
4494
4493
4492
4491
4490
4489
4488
4487
4486
4485
4484
4483
4482
4481
4480