import math
# axx+byy+cx+dy+e=f
a,b,c,d,e,f=map(int,input().split())

b/=a
c/=a
d/=a
e/=a
f/=a
a/=a
f-=e
# xx+yy+cx+dy=f

f+=(0.5*c)**2+(0.5*d)**2
# (x+0.5c)^2+(y+0.5d)^2=f
print(math.sqrt(f))