#include <bits/stdc++.h>
using namespace std;
int main() {
  int t;
  cin >> t;
  while (t--) {
    int n;
    cin >> n;
    int arr[n], k, j;
    k = 0;
    for (int i = 1; i <= n; i++) {
      cin >> arr[i];
      if (arr[i] % 2 == 0) {
        k = 1;
        j = i;
      }
    }
    if (k)
      cout << "1" << endl << j << endl;
    else if (n > 1)
      cout << "2" << endl << "1" << ' ' << "2" << endl;
    else
      cout << "-1" << endl;
  }
}
