from collections import defaultdict
def factorize(x):
 i=2
 p=defaultdict(int)
 while i*i<=x:
  while x%i==0:
   x//=i
   p[i]+=1
  i+=1
 if x>1:
  p[x]+=1
 return p
	
x,a,y,b=map(int,input().split())
X=factorize(x)
Y=factorize(y)
ok=True
for key in Y:
 if Y[key]*b>X[key]*a:
  ok=False
  break
print('Yes' if ok else 'No')