#include <bits/stdc++.h>   using namespace std;   void cal(long long number, long long x, long long s) {     long long d = number ^ x;     long long temp = 2 * number - (s + d);     if (temp % 2 == 0) {       cout << 3 << endl;       cout << d <<     << temp / 2 <<     << temp / 2 << endl;     }     if (temp % 2 == 1) {       number -= 1;       d = number ^ x;       temp = 2 * number - (s + d);       cout << 3 << endl;       cout << d <<     << temp / 2 <<     << temp / 2 << endl;     }   }   void solve() {     long long n;     cin >> n;     vector<long long> a(n);     long long s = 0, x = 0, number = 0;     for (long long i = 0; i < 57; i++) {       number = number | 1LL << i;     }     for (long long i = 0; i < n; i++) {       cin >> a[i];       s = s + a[i];       x = x ^ a[i];     }     cal(number, x, s);   }   signed main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     long long t = 1;     cin >> t;     while (t--) solve();     return 0;   }   