import math
P, Q = map(int, input().split())

def f(n):
    return n*n - Q*n*math.log2(n) - P <= 0

# True になる最大の n は？
ok = 1
ng = 10**20
#cnt = 0
while abs(ok - ng) > 10**(-5):
    mid = (ok + ng)/2
    if f(mid):
        ok = mid
    else:
        ng = mid

    #cnt += 1
    #if cnt > 100:
    #    break

print(ok)