import math
a,b=(float (i) for i in input (). split ())
a*=a
b*=b
if a==b:
    m=a+b
else:
    if a>b:
        m=a
        ot=b
    elif b>a:
        m=b
        ot=a
    m-=ot
m=math.sqrt(m)
print (m)