func main()
	var l: int :: cui@inputInt()
	var r: int :: cui@inputInt()
	var m: int :: cui@inputInt()
	var k: int :: cui@inputInt()
	
	var ans: bool ::
	|l * k % m = 0
	||k = 0
	||r * k % m = 0
	||r * k / m > l * k / m
	do cui@print(ans ?("Yes\n", "No\n"))
end func