func main()
	var ss: [][]char :: cui@input().split(" ")
	var a: float :: ss[0].toFloat(&)
	var b: float :: ss[1].toFloat(&)
	var dx: float :: (b - a) / 1000000.0
	var ans: float :: 0.0
	for i(0, 1000000)
		var x: float :: a + i $ float * dx
		do ans :- (x - a) * (x - b) * dx
	end for
	do cui@print("\{ans}\n")
end func