package no268;

import java.util.Arrays;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int[] l = new int[3];
		for(int i=0;i<3;i++) {
			l[i] = sc.nextInt();
		}
		Arrays.sort(l);
		int[] a = new int[3];
		for(int i=0;i<3;i++) {
			a[i] = sc.nextInt();
		}
		Arrays.sort(a);
		System.out.println(2 * ((l[1] + l[2]) * a[0] + (l[0] + l[2]) * a[1] + (l[0] + l[1]) * a[2]));
	}

}