import math
p,q = map(int,input().split())

low = 1
high = 10**20
tmp = 0

while low+10**(0) < high:
    tmp = 0
    mid = (low + high) / 2
    #print(mid)
    
    #for i in range(n):
    #    tmp += max(0,af[i][1] - mid // af[i][2])
    #print(tmp)
    
    if mid**2 >= p+q*mid*math.log2(mid):
        high = mid
    else:
        low = mid
        
print(high)