import math
import sys

sys.setrecursionlimit(100000)

p, q = 0, 0

def main():
    global p, q
    p, q = map(int, input().split())
    ans = solve()
    print(ans)

def f(n):
    return n * n - q * n * math.log2(n) - p

def solve():
    return binaryserch(f, 0, 10 ** 100)

def binaryserch(func, _min, _max):
    #print(_min, _max)
    tmp = (_min + _max) / 2
    ans = func(tmp)
   #print('ans', tmp, ans)
    if _max - _min < 10 ** -5:
        return tmp
    if ans > 0:
        return binaryserch(func, _min, tmp)
    elif func(tmp) < 0:
        return binaryserch(func, tmp, _max)

if __name__ == '__main__':
    main()