# Programmer: Sriram Pemmaraju
# Date: Feb 13, 2015

# Get input
s = float(input())
eps = float(input())

# Initialize the first two terms x_0 and x_1
oldX = s/2
newX = (oldX + s/oldX)/2

# Repeatedly construct x_i from x_{i-1} using the formula in the handout.
# Do this while two consecutive terms are far from each other
while abs(oldX - newX) > eps:
    oldX = newX
    newX = (oldX + s/oldX)/2

print(newX)