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

taka=int((c+b-1)/b)

aoki=int((a+d-1)/d)



if taka<=aoki:

    print("Yes")

else:

    print("No")
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()))
taka = int((c + b - 1) / b)
aoki = int((a + d - 1) / d)
if taka <= aoki:
    print("Yes")
else:
    print("No")

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()

-taka = int((c + b - 1) / b) -aoki = int((a + d - 1) / d) -if taka <= aoki: -    print("Yes") -else: -    print("No") +while True: +    c -= b +    if c <= 0: +        print("Yes") +        exit() +    a -= d +    if a <= 0: +        print("No") +        exit()