#pragma comment(linker,"/STACK:1024000000,1024000000")

#include<iostream>

#include<cstdio>

#include<string>

#include<cstring>

#include<vector>

#include<cmath>

#include<queue>

#include<stack>

#include<map>

#include<set>

#include<algorithm>

#include <stack>

using namespace std;

const int SZ=1e7+,INF=0x7FFFFFFF;

typedef long long lon;

int main()

{

    std::ios::sync_with_stdio();

    int a,b,c,d,e,f;

    cin>>a>>b>>c>>d>>e>>f;

    cout<<((a+f)*(a+b)+(c+d)*(d+e)-a*a-d*d)<<endl;

    return ;

}