from decimal import *
a,b,c,d,e,f = input().split()

if a != b:
    print (achimi)

a = Decimal(a)
b = Decimal(b)
c = Decimal(c)
d = Decimal(d)
e = Decimal(e)
f = Decimal(f)

f -= e

c /= a
d /= a
f /= a

f += (c**Decimal('2'))/Decimal('4')
f += (d**Decimal('2'))/Decimal('4')



#print (a,f)

print (abs(f)**Decimal('0.5'))