func_code_string: #include <bits/stdc++.h>   using namespace std;   using LL = long long;   const double PI = 3.14159265358979323846;   const int INF = 0x3f3f3f3f;   const int MOD = 1e9 + 7;   void solve() {     int n;     cin >> n;     vector<int> bit(64);     LL sum = 0, ans = 0;     for (int i = 0; i < int(n); ++i) {       LL num;       cin >> num;       sum += num;       ans ^= num;     }     cout << 2 << endl;     cout << ans <<     << ans + sum << endl;   }   int main() {     int t;     cin >> t;     while (t--) {       solve();     }     return 0;   }   