import math

a,b,c,d =list(map(int,input().split()))

print(('Yes'if math.ceil(a/d)>=math.ceil(c/b) else 'No'))
a,b,c,d =list(map(int,input().split()))

while True:

    c=c-b

    if c<=0:

        print('Yes')

        break

    a=a-d

    if a<=0:

        print('No')

        break
import math

a, b, c, d = list(map(int, input().split()))
print(("Yes" if math.ceil(a / d) >= math.ceil(c / b) else "No"))

a, b, c, d = list(map(int, input().split()))
while True:
    c = c - b
    if c <= 0:
        print("Yes")
        break
    a = a - d
    if a <= 0:
        print("No")
        break

-import math - -print(("Yes" if math.ceil(a / d) >= math.ceil(c / b) else "No")) +while True: +    c = c - b +    if c <= 0: +        print("Yes") +        break +    a = a - d +    if a <= 0: +        print("No") +        break