from math import log2

def is_ok(n):
    return n * n <= q * log2(n) * n + p

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

ok = 1
ng = 1e11

while ng - ok > 0.000001:
    m = (ok + ng) / 2
    if is_ok(m):
        ok = m
    else:
        ng = m

print(ok)