A square on a chessboard is identified by two numbers (a, b) from 1 to 8. The first is the column, the second is the row. Given two squares, determine if a king can move from the first to the second in one move.

Four integers from 1 to 8 are given: the first two specify the starting square, the other two the target square. The start and end squares are different. Each number is on a separate line.

Output "YES" if the king can move from the first square to the second in one move, otherwise output "NO".

[{'input': '4\n4\n5\n5', 'output': 'YES'}]