func main()
	var a: float :: cui@inputFloat()
	var b: float :: cui@inputFloat()
	var c: float :: cui@inputFloat()
	var d: float :: cui@inputFloat()
	var e: float :: cui@inputFloat()
	var f: float :: cui@inputFloat()
	
	var ans: float :: (f - e + (c ^ 2.0 + d ^ 2.0) / 4.0 / a ^ 2.0) ^ 0.5
	do cui@print("\{ans.toStrFmt(".15f")}\n")
end func