Y \ X
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
5000
4999
4998
4997
4996
4995
4994
4993
4992
4991
4990
4989
4988
4987
4986
4985
4984
4983
4982
4981
4980