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package javaapplication12;

import java.util.Scanner;

public class JavaApplication12 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        double width = Double.parseDouble(scanner.next());
        double height = Double.parseDouble(scanner.next());

        double x1 = 0;
        double x2 = width;
        double y1 = 0;
        double y2 = height;

        double p1 = Math.abs(x1 - x2);
        double p2 = Math.abs(y1 - y2);

        double p3 = p1 * p2;
        double p4 = 2 * (p1 + p2);

        System.out.printf("%.2f\n", p3);
        //System.out.printf("%.2f", p4);

    }
}