#include <bits/stdc++.h>
using namespace std;
template <class T>
bool ckmin(T& a, const T& b) {
  return b < a ? a = b, 1 : 0;
}
template <class T>
bool ckmax(T& a, const T& b) {
  return a < b ? a = b, 1 : 0;
}
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const long double pii = 3.14159265359;
const int MOD = 1000000007;
const char nl = '\n';
const int MX = 200001;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int T;
  cin >> T;
  while (T-- != 0) {
    int N;
    cin >> N;
    vector<int> v(2);
    for (int x = 0; x < (N); x++) {
      int nb;
      cin >> nb;
      v[nb]++;
    }
    if (v[0] >= v[1]) {
      cout << v[0] << nl;
      for (int x = 0; x < (v[0]); x++) cout << 0 << ' ';
    } else {
      cout << v[1] - v[1] % 2 << nl;
      for (int x = 0; x < (v[1] - v[1] % 2); x++) {
        cout << 1 << ' ';
      }
    }
    cout << nl;
  }
  return 0;
}
