import math

def solve(mid):
    taka = mid ** 2
    tei = p + q * mid * math.log2(mid)
    return taka <= tei

p, q = map(int, input().split())

ok = 1
ng = 10 ** 18
cnt = 0
while cnt < 10000:
    mid = (ok + ng) / 2
    if solve(mid):
        ok = mid
    else:
        ng = mid
    cnt += 1

print(ok)