#include <bits/stdc++.h>   using namespace std;   void _print(long long t) { cerr << t; }   void _print(int t) { cerr << t; }   void _print(string t) { cerr << t; }   void _print(char t) { cerr << t; }   void _print(long double t) { cerr << t; }   void _print(double t) { cerr << t; }   void _print(unsigned long long t) { cerr << t; }   template <class T, class V>   void _print(pair<T, V> p);   template <class T>   void _print(vector<T> v);   template <class T>   void _print(vector<vector<T>> v);   template <class T>   void _print(set<T> v);   template <class T, class V>   void _print(map<T, V> v);   template <class T>   void _print(multiset<T> v);   template <class T, class V>   void _print(pair<T, V> p) {     cerr <<  { ;     _print(p.first);     cerr <<  , ;     _print(p.second);     cerr <<  } ;   }   template <class T>   void _print(vector<T> v) {     cerr <<  [  ;     for (T i : v) {       _print(i);       cerr <<    ;     }     cerr <<  ] ;   }   template <class T>   void _print(vector<vector<T>> v) {     cerr <<  ==>  << endl;     for (vector<T> vec : v) {       for (T i : vec) {         _print(i);         cerr <<    ;       }       cerr << endl;     }   }   template <class T>   void _print(set<T> v) {     cerr <<  [  ;     for (T i : v) {       _print(i);       cerr <<    ;     }     cerr <<  ] ;   }   template <class T>   void _print(multiset<T> v) {     cerr <<  [  ;     for (T i : v) {       _print(i);       cerr <<    ;     }     cerr <<  ] ;   }   template <class T, class V>   void _print(map<T, V> v) {     cerr <<  [  ;     for (auto i : v) {       _print(i);       cerr <<    ;     }     cerr <<  ] ;   }   mt19937_64 rang(       chrono::high_resolution_clock::now().time_since_epoch().count());   int rng(int lim) {     uniform_int_distribution<int> uid(0, lim - 1);     return uid(rang);   }   const int INF = 0x3f3f3f3f;   const int mod = 1e9 + 7;   long long mod_exp(long long a, long long b) {     a %= mod;     if (a == 0) return 0LL;     long long res = 1LL;     while (b > 0) {       if (b & 1) res = (res * a) % mod;       a = (a * a) % mod;       b >>= 1;     }     return res;   }   long long mod_inv(long long a) { return mod_exp(a, mod - 2); }   long long GCD(long long a, long long b) { return (b == 0) ? a : GCD(b, a % b); }   void solve() {     long long a1, a2, a3, a4, a5, a6;     cin >> a1 >> a2 >> a3 >> a4 >> a5 >> a6;     cout << ((a1 + a2 + a3) * (a1 + a2 + a3)) - (a1 * a1) - (a3 * a3) - (a5 * a5);   }   int main() {     ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);     srand(chrono::high_resolution_clock::now().time_since_epoch().count());     int t = 1;     while (t--) {       solve();     }     return 0;   }   