Accessible Hexagonal Grid

In this problem, you are given two cells on an infinite hexagonal grid. Each cell is described by its coordinates \( (x_1, y_1) \) and \( (x_2, y_2) \). Two cells are considered accessible from one another if the parity of the sum of coordinates of the two cells is the same, i.e., if

\( (x_1+y_1) \bmod 2 = (x_2+y_2) \bmod 2 \)

If the condition holds, output YES, otherwise output NO.

inputFormat

The input consists of a single line containing four space-separated integers: x1, y1, x2, and y2.

outputFormat

Output a single line containing YES if the two cells are accessible from one another, or NO otherwise.

0 0 2 2

YES