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

 

while C or A >= 0:

    C -= B

    A -= D

    if C <= 0:

        print('Yes')

        break

    if  A <= 0:

        print('No')

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



while c or a >= 0:

    c -= b

    a -= d

    if c <= 0:

        print("Yes")

        break

    if a <= 0:

        print("No")

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

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

-A, B, C, D = list(map(int, input().split())) -while C or A >= 0: -    C -= B -    A -= D -    if C <= 0: +a, b, c, d = list(map(int, input().split())) +while c or a >= 0: +    c -= b +    a -= d +    if c <= 0: -    if A <= 0: +    if a <= 0: