func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     long long t;     cin >> t;     while (t--) {       long long n;       cin >> n;       long long sum = 0;       long long x = 0;       while (n--) {         long long s;         cin >> s;         sum += s;         x ^= s;       }       cout << 2 <<   n ;       cout << x <<     << sum + x << endl;     }   }   