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