#include <iostream>
#include <stdio.h>
#include <vector>
#include <algorithm>

int main() {
	std::vector<int> vec1,vec2;
	int l1,l2,l3,r,b,y;
	scanf("%d %d %d %d %d %d",&l1,&l2,&l3,&r,&b,&y);
	vec1.push_back(l1+l2);
	vec1.push_back(l1+l3);
	vec1.push_back(l2+l3);
	vec2.push_back(r);
	vec2.push_back(b);
	vec2.push_back(y);
	std::sort(vec1.begin(),vec1.end());
	std::sort(vec2.begin(),vec2.end());
	std::cout<<2*(vec1[2]*vec2[0]+vec1[1]*vec2[1]+vec1[0]*vec2[2])<<"\n";

}