#include <iostream>
#include <algorithm>
#include <vector>
#include <deque>
#include <string>
#include <tuple>
#include <functional>
#include <numeric>
#include <cmath>
#include <iomanip>
#include <map>
#include <random>
//#include "toollib.h"
#define INT_MAX 2147483647
#define Loop(i, n) for(int i = 0; i < (int)n; i++)
#pragma warning (disable:4018)

using namespace std;
typedef long long int lint;

typedef struct {
	int x;
	int y;
}coordinate;

//***** Main Program *****

int main() {
	int L1, L2, L3;
	vector<int> L(3);
	vector<int> R(3);
	cin >> L1 >> L2 >> L3;
	L[0] = (L1 + L2) * 2;
	L[1] = (L2 + L3) * 2;
	L[2] = (L3 + L1) * 2;
	sort(L.begin(), L.end());
	cin >> R[0] >> R[1] >> R[2];
	sort(R.begin(), R.end(), greater<int>());
	cout << L[0] * R[0] + L[1] * R[1] + L[2] * R[2] << endl;
	return 0;
}