#define _USE_MATH_DEFINES
#include <algorithm>
#include <cstdio>
#include <functional>
#include <iostream>
#include <cfloat>
#include <climits>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <time.h>
#include <vector>
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> i_i;
typedef pair<ll, int> ll_i;
typedef pair<double, int> d_i;
typedef pair<ll, ll> ll_ll;
typedef pair<double, double> d_d;
struct edge { int u, v; ll w; };
 
ll MOD = 1000000007;
ll _MOD = 1000000009;
double EPS = 1e-10;
int INF = INT_MAX / 10;

int main() {
	int a, b, c; cin >> a >> b >> c;
	vector<int> v(3);
	v[0] = a + b; v[1] = b + c; v[2] = c + a;
	sort(v.begin(), v.end());
	vector<int> w(3);
	cin >> w[0] >> w[1] >> w[2];
	sort(w.begin(), w.end());
	cout << 2 * (v[0] * w[2] + v[1] * w[1] + v[2] * w[0]);
}