$P, $Q = gets.split(" ").map{|s| s.to_i}

def lose?(n)
	n**2 > ($P + $Q * n * Math.log(n, 2))
end

n = 1
while not lose?(n) do
	n *= 2
end

lb = n / 2.0
ub = n.to_f

while ub - lb >= 10**(-5) do
	mid = (lb + ub) / 2.0
	if lose?(mid) then
		ub = mid
	else
		lb = mid
	end
end

puts lb