import sys

input = sys.stdin.readline

from collections import *



A, B, C, D = list(map(int, input().split()))



while True:

    C -= B

    

    if C<=0:

        print('Yes')

        exit()

    

    A -= D

    

    if A<=0:

        print('No')

        exit()
A, B, C, D = list(map(int, input().split()))

c1 = (C+B-1)//B

c2 = (A+D-1)//D



if c1<=c2:

    print('Yes')

else:

    print('No')
import sys

input = sys.stdin.readline
from collections import *

A, B, C, D = list(map(int, input().split()))
while True:
    C -= B
    if C <= 0:
        print("Yes")
        exit()
    A -= D
    if A <= 0:
        print("No")
        exit()

A, B, C, D = list(map(int, input().split()))
c1 = (C + B - 1) // B
c2 = (A + D - 1) // D
if c1 <= c2:
    print("Yes")
else:
    print("No")

-import sys - -input = sys.stdin.readline -from collections import * - -while True: -    C -= B -    if C <= 0: -        print("Yes") -        exit() -    A -= D -    if A <= 0: -        print("No") -        exit() +c1 = (C + B - 1) // B +c2 = (A + D - 1) // D +if c1 <= c2: +    print("Yes") +else: +    print("No")