import java.util.Arrays;
import java.util.Comparator;
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] = Integer.parseInt(sc.next());
		Integer[] r = new Integer[3];
		for (int i = 0; i < 3; i++)
			r[i] = Integer.parseInt(sc.next());
		Arrays.sort(l);
		Arrays.sort(r, Comparator.reverseOrder());
		int ans = r[0] * (l[0] + l[1]) * 2;
		if (l[1] + l[2] > l[2] + l[0]) {
			int t = r[1];
			r[1] = r[2];
			r[2] = t;
		}
		ans += r[1] * (l[1] + l[2]) * 2;
		ans += r[2] * (l[2] + l[0]) * 2;
		System.out.println(ans);
	}
}