#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  int t;
  cin >> t;
  while (t--) {
    long long n, s = 0, x = 0;
    cin >> n;
    int a[n];
    for (int i = (0); i < (n); ++i) {
      cin >> a[i];
      s += a[i];
      x ^= a[i];
    }
    cout << 2 << '\n';
    cout << x << " " << (s + x) << '\n';
  }
  return 0;
}
