#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <algorithm>
#include <string>
#include <cmath>
#include <cstdio>
#include <iomanip>
#include <fstream>
#include <cassert>
#include <cstring>
#include <unordered_set>
#include <unordered_map>
#include <numeric>
#include <ctime>
#include <bitset>
#include <complex>
#include <random>

using namespace std;

#define int long long

void solve() {
    int n;
    cin >> n;
    vector<int> a(n);
    for (auto &t : a) {
        cin >> t;
    }
    int cs = 0;
    int cx = 0;
    for (auto t : a) {
        cs += t;
        cx ^= t;
    }
    //cs + x = 2 * (cx ^ x)
    vector<int> ans;
    if (cx > 0) ans.push_back(cx);
    cs += cx;
    ans.push_back(cs);
    cout << ans.size() << endl;
    for (auto t : ans) {
        cout << t << ' ';
    }
    cout << endl;
}

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    int q;
    cin >> q;
    while (q--) {
        solve();
    }
}