def prime_fact(n)
	ans = Hash.new(0)
	i = 2
	while i*i <= n do
		if n % i != 0 then
			i += 1
			next
		end
		tmp = 0
		while n % i == 0 do
			tmp += 1
			n /= i
		end
		ans[i] = tmp
		i += 1
	end
	ans[n] = 1 if n != 1 
	ans
end

X, A, Y, B = gets.split(" ").map{|s| s.to_i}

x = prime_fact(X)
y = prime_fact(Y)

result = true
y.each {|k, v|
	if x[k] * A < y[k] * B then
		result = false
		break
	end
}

puts result ? "Yes" : "No"