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

import math
def check(N):
    if N**2<=P+Q*N*math.log2(N):
        return True
    else:
        return False

OK=1
NG=1<<62

for rep in range(10**4):
    mid=(OK+NG)/2
    if check(mid)==True:
        OK=mid
    else:
        NG=mid
print(mid)