#include <bits/stdc++.h>
using namespace std;
void solve() {
  int x, c = 0, l = 0;
  vector<int> v;
  cin >> x;
  int ar[x];
  for (int i = 0; i < x; i++) {
    cin >> ar[i];
    if (ar[i] % 2 == 0) {
      c = i + 1;
    }
  }
  if (c != 0) {
    cout << 1 << endl << c << endl;
  } else if (c == 0) {
    if (x == 1)
      cout << -1 << endl;
    else {
      for (int i = 0; i < x; i++) {
        if (ar[i] % 2 == 1 && l < 2) {
          v.push_back(i + 1);
          l++;
          if (l == 2) break;
        }
      }
      cout << 2 << endl << v[0] << " " << v[1] << endl;
    }
  } else
    cout << 1 << endl << c << endl;
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  short t;
  cin >> t;
  while (t--) {
    solve();
  }
  return 0;
}
