Mr. Pr and Ms. Ad are at a and b respectively on an infinite number line. Mr. Pr wants to meet Ms. Ad.

Mr. Pr can choose to move c or d units in 1 second. If Mr. Pr moves c units then Ms. Ad will move d units and vice versa. (Both of them always moved in positive x-direction).

You have to determine if Mr. Pr can meet with Ms. Ad after some integral amount of time, given that Mr. Pr chooses optimally. Note that meeting after a fractional amount of time does not count.

Constraints

1a,b,c,d109

Input Format

Four space separated integers, a, b, c, and d.

Output Format

Output a single line containing "YES" if Mr. Pr meets with Ms. Ad, otherwise "NO".

Sample #1

Input

3 4 1 2

Output

YES

Explanation

Mr. Pr will move 2 units in the first second

and Ms. Ad moves 1 unit simultaneously

and they meet.

Sample #2

Input

10 20 3 7

Output

NO

Explanation

It is impossible to meet

(fractional time is not allowed)