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
2500
2499
2498
2497
2496
2495
2494
2493
2492
2491
2490
2489
2488
2487
2486
2485
2484
2483
2482
2481
2480