#!/usr/bin/env python3 import scipy.integrate def compute_area(a, b): res = scipy.integrate.quad(lambda x: -(x - a) * (x - b), a, b) return res[0] def main(): a, b = (int(z) for z in input().split()) area = compute_area(a, b) print("{:.12f}".format(area)) if __name__ == "__main__": main()