Kangaroo

#!/bin/python3

import math
import os
import random
import re
import sys

# Complete the kangaroo function below.
def kangaroo(x1, v1, x2, v2):
    if v1 > v2 or v1 < v2:
        a=abs((x2-x1)/(v1-v2))
    #print(a)
    for i in range(0,10000):
        if x1 < x2 and v1 > v2  or x1 > x2 and v1 < v2:
            if a in range(1,10000):
                return "YES"
            else:
                return "NO"

        
        else:
            return "NO"    
        









if __name__ == '__main__':
    fptr = open(os.environ['OUTPUT_PATH'], 'w')

    x1V1X2V2 = input().split()

    x1 = int(x1V1X2V2[0])

    v1 = int(x1V1X2V2[1])

    x2 = int(x1V1X2V2[2])

    v2 = int(x1V1X2V2[3])

    result = kangaroo(x1, v1, x2, v2)

    fptr.write(result + '\n')

    fptr.close()