def prime_fact(n)

	ans = Hash.new(0)

	prime = 2.upto(n).to_a
	2.upto(n) {|i|
		if prime.include?(i) then
			k = 2
			while k * i <= n do
				prime.delete(k*i)
				k += 1
			end
		end
	}

	if prime.include?(n)
		ans[n] = 1
	else
		i = 0	
		while i < prime.length do
			p = prime[i]
			if n % p == 0
				ans[p] += 1
				n /= p
			else
				i += 1
			end
		end
	end
	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"