def main():
  X,A,Y,B = map(int, input().split( ))
  j=1
  S = collections.Counter(prime_factorize(X))
  T = collections.Counter(prime_factorize(Y))
  for num in range(len(T)):
    i=T.most_common()[num][0]
    if A*S[i] < B*T[i]:
     print("No")
     j=-1
     break
  if j>0:
    print("Yes")

if __name__ == '__main__':
  main()