p,q=map(int,input().split())
from math import log2
def f(n):
    if n**2<=p+q*n*log2(n):
        return True
lo=0
hi=10**15
for i in range(10000):
    mi=(hi+lo)/2
    if f(mi):
        lo=mi
    else:
        hi=mi
print(lo)