import decimal
D = decimal.Decimal

a,b,c,d,e,f = input().split()
a = D(a)
b = D(b)
c = D(c)
d = D(d)
e = D(e)
f = D(f)

l ,r= D('0'), D('1000000000')
for _ in range(1000000):
    mid = D((l + r)/2)
    if 4 * a * a * mid * mid < 4 * a * (f-e) + c * c + d * d: l = mid
    else :r = mid
print(l)