import math
from decimal import Decimal


def check(n, p, q):
    if n / q >= 100:
         return False
    a = p + q * n * Decimal.ln(n) / Decimal.ln(Decimal(2))
    b = n * n
    return b <= a

def main():
    P, Q = map(int, input().split())
    p, q = Decimal(P), Decimal(Q)

    ok, ng = Decimal(1), Decimal(1e16)
    for _ in range(10000):
        n = (ok + ng) / Decimal(2)
        if check(n, p, q):
            ok = n
        else:
            ng = n
    print(ok)


if __name__ == '__main__':
    main()