package main

import . "fmt"
import . "math"

func main() {
	var a,b,c,d,e,f float64
	Scan(&a,&b,&c,&d,&e,&f)
	r := Sqrt((f-e)/a + Pow(c/(2*a), 2) + Pow(d/(2*a), 2))
	Printf("%.20f\n", r)
}