import sys
input = sys.stdin.readline
from collections import *

def factorize(n):
    fct = defaultdict(int)
    
    for i in range(2, int(n**0.5)+1):
        c = 0
        
        while n%i==0:
            n //= i
            c += 1
            
        if c>0:
            fct[i] = c
    
    if n>1:
        fct[n] = 1
    
    return fct

X, A, Y, B = map(int, input().split())
fctX = factorize(X)
fctY = factorize(Y)
ok = True

for k in fctY:
    if fctX[k]*A<fctY[k]*B:
        ok = False

if ok:
    print('Yes')
else:
    print('No')