import math

def find_max_n():
    p, q = map(int, input().split())

    def is_ok(n):
        if n < 1e-9:
            return False  # log2(0) is undefined; minimal n considered
        try:
            left = n ** 2
            log_val = math.log2(n)
            right = p + q * n * log_val
            return left <= right
        except:
            return False  # in case n is too small, but shouldn't happen here

    # Find an appropriate upper bound
    high = 1.0
    while is_ok(high):
        high *= 2

    # Binary search between high/2 and high
    low = high / 2
    for _ in range(1000):
        mid = (low + high) / 2
        if is_ok(mid):
            low = mid
        else:
            high = mid

    # Print with 9 decimal places
    print("{0:.9f}".format(low))

find_max_n()