#include <bits/stdc++.h>
using namespace std;
void solve() {
  int n;
  cin >> n;
  vector<int> v(n);
  for (int i = 0; i < n; i++) {
    cin >> v[i];
  }
  int odd = 0;
  int prev = -1;
  for (int i = 0; i < n; i++) {
    if (!(v[i] & 1)) {
      cout << "1" << endl;
      cout << i + 1 << endl;
      return;
    } else {
      odd++;
      if (odd == 2) {
        cout << "2" << endl;
        cout << prev + 1 << " " << i + 1 << endl;
        return;
      }
      prev = i;
    }
  }
  cout << "-1" << endl;
}
int main() {
  int t;
  cin >> t;
  while (t--) {
    solve();
  }
}
