#include <bits/stdc++.h>
using namespace std;
int main() {
  long long t, n, k;
  cin >> t;
  while (t--) {
    cin >> n;
    int arr[n];
    int c1 = 0;
    for (int i = 0; i < n; i++) {
      cin >> arr[i];
      if (arr[i] == 1) c1++;
    }
    if (n - c1 >= c1) {
      cout << n - c1 << endl;
      for (int i = 0; i < n - c1; i++) {
        cout << "0 ";
      }
      cout << endl;
    } else {
      if (c1 % 2 == 0) {
        cout << c1 << endl;
        for (int i = 0; i < c1; i++) {
          cout << "1 ";
        }
        cout << endl;
      } else {
        cout << c1 - 1 << endl;
        for (int i = 0; i < c1 - 1; i++) {
          cout << "1 ";
        }
        cout << endl;
      }
    }
  }
}
