func_code_string: #include <bits/stdc++.h>   using namespace std;   int a, b, c, d, e, f;   void read() { cin >> a >> b >> c >> d >> e >> f; }   void solve() {     int res = 0;     res += (a + b + f) * (a + b + f);     res -= f * f;     res -= b * b;     res -= d * d;     cout << res << endl;   }   int main() {     read();     solve();     return 0;   }   