#include <bits/stdc++.h>
using namespace std;
int main() {
  int t;
  cin >> t;
  while (t--) {
    int n;
    cin >> n;
    int a[n];
    for (int i = 0; i < n; i++) cin >> a[i];
    int d[2] = {0}, f = 0, cnt = 0, p = 0, ev = 0;
    for (int i = 0; i < n; i++) {
      if (a[i] % 2 != 0) {
        cnt++;
        if (f == 0 && cnt <= 2) {
          d[0] = i + 1;
          f = 1;
        } else if (f == 1 && cnt <= 2)
          d[1] = i + 1;
        if (cnt == 2) break;
      } else {
        ev++;
        p = i + 1;
        break;
      }
    }
    if (ev != 0) {
      cout << ev << endl;
      cout << p << endl;
    } else if (ev == 0 && cnt == 2) {
      cout << cnt << endl;
      cout << d[0] << " " << d[1] << endl;
    } else
      cout << "-1" << endl;
  }
  return 0;
}
