func_code_string: #include <bits/stdc++.h>   using namespace std;   namespace std {   template <>   struct hash<pair<int, int> > {     size_t operator()(const pair<int, int>& x) const {       long long P = 38923, Q = 109797901;       return (size_t)((x.first * P + x.second) % Q);     }   };   };  // namespace std   template <class T>   using pqg = priority_queue<T, vector<T>, greater<T> >;   template <typename T, typename second>   ostream& operator<<(ostream& os, const pair<T, second>& v) {     os <<  (  << v.first <<  ,   << v.second <<  ) ;     return os;   }   template <typename T>   void print(T t) {     cout << t << endl << flush;   }   template <typename T, typename... Args>   void print(T t, Args... args) {     cout << t <<    ;     print(args...);   }   int main() {     int T;     cin >> T;     for (auto t = 0; t < T; t += 1) {       int n;       cin >> n;       vector<int> a(n);       long long A, B;       A = 0;       B = 0;       for (auto i = 0; i < n; i += 1) {         cin >> a[i];         A += a[i];         B ^= a[i];       }       print(2);       print(B, A + B);     }   }   