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



while True:

  C-=B

  if C<=0:

    break

  A-=D

  if A<=0:

    break



if A>=C:

  print("Yes")

else:

  print("No")
A,B,C,D=list(map(int,input().split()))

k1=0

k2=0



if C%B==0:

  k1=C//B

else:

  k1=C//B+1

if A%D==0:

  k2=A//D

else:

  k2=A//D+1

if k1<=k2:

  print("Yes")

else:

  print("No")

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

A, B, C, D = list(map(int, input().split()))
k1 = 0
k2 = 0
if C % B == 0:
    k1 = C // B
else:
    k1 = C // B + 1
if A % D == 0:
    k2 = A // D
else:
    k2 = A // D + 1
if k1 <= k2:
    print("Yes")
else:
    print("No")

-while True: -    C -= B -    if C <= 0: -        break -    A -= D -    if A <= 0: -        break -if A >= C: +k1 = 0 +k2 = 0 +if C % B == 0: +    k1 = C // B +else: +    k1 = C // B + 1 +if A % D == 0: +    k2 = A // D +else: +    k2 = A // D + 1 +if k1 <= k2: