import sys; input = sys.stdin.buffer.readline
sys.setrecursionlimit(10**7)
from collections import defaultdict
con = 10 ** 9 + 7; INF = float("inf")
import math

def getlist():
	return list(map(int, input().split()))

def Binary_Search(P, Q):
	#初期化
	left = 0
	right = 10 ** 18
	
	#二分探索
	while right - left > 10 ** (-5):
		mid = (left + right) / 2
		val = mid ** 2 - (P + Q * mid * math.log(mid, 2))
		# print(mid)
		if val <= 0:
			left = mid
		else:
			right = mid

	return mid


#処理内容
def main():
	P, Q = getlist()
	ans = Binary_Search(P, Q)
	print(ans)
	
if __name__ == '__main__':
	main()