x,a,y,b = map(int,input().split())
dx = {}
dy = {}
for i in range(2,int(x**0.5)+1):
    if x%i:
        continue
    c = 0
    while x%i == 0:
        c += 1
        x //= i
    dx[i] = c 
if x != 1:
    dx[x] = 1
for i in range(2,int(y**0.5)+1):
    if y%i:
        continue
    c = 0
    while y%i == 0:
        c += 1
        y //= i
    dy[i] = c 
if y != 1:
    dy[y] = 1
for k,v in dy.items():
    if dx.get(k,0)*a < v*b:
        print("No")
        exit()
print("Yes")