import sys
input=sys.stdin.readline
def I(): return int(input())
def MI(): return map(int, input().split())
def LI(): return list(map(int, input().split()))

def main():
    mod=10**9+7
    a,b,c,d,e,f=MI()
    r2=f-e + (c*c)/(4*a) + (d*d)/(4*b)
    
    print(r2**0.5)


main()