a,b,c,d,e,f=map(int,input().split())
"""
ax**2+by**2+cx+dy+e=f
a=b
a(x**2 + c/ax + (c/2a)**2) + a(x**2 + d/ax + (d/2a)**2) = f - e +  (c/2a)**2 + (d/2a)**2
(x**2 + c/ax + (c/2a)**2) + (x**2 + d/ax + (d/2a)**2) = (f - e +  (c/2a)**2 + (d/2a)**2) / a

"""
tmp=f-e+(c/(2*a))**2+(d/(2*a))**2
tmp/=a
print(tmp**0.5)