import math
a, b = map(int,input().split())

x_1 = math.sqrt(a**2 + b**2)
if a - b > 0:
    x_2 = math.sqrt(a**2 - b**2)
elif a - b == 0:
    x_2 = x_1
else:
    x_2 = math.sqrt(b**2 - a**2)

if x_1 - x_2 <= 0:
    print(x_1)
else:
    print(x_2)