import java.io.PrintWriter;
import java.util.*;

public class Main {

    Scanner sc = new Scanner(System.in);

    PrintWriter out = new PrintWriter(System.out);

    public static void main(String[] args) {
        new Main().run();
    }

    void run() {

        double a = sc.nextDouble();
        double b = sc.nextDouble();

        if (b < a) {
            double tmp = b;
            b = a;
            a = tmp;
        }

        double x3 = (double)1 / (double)3;
        double x2 = (a*(-1)+b*(-1)) / (double)2;
        double x1 = a * b;

        double ans = 0;

        ans = x3*(Math.pow(b, 3)-Math.pow(a, 3))+x2*(Math.pow(b, 2)-Math.pow(a, 2))+x1*(b-a);

        out.print(Math.abs(ans));
        out.flush();

    }

}