#include <bits/stdc++.h>
using namespace std;
int t, ou, ji;
int n, a[200];
int main() {
  cin >> t;
  while (t--) {
    ou = 0, ji = 0;
    cin >> n;
    int x[200], y[200], t1 = 0, t2 = 0;
    for (int i = 1; i <= n; i++) {
      cin >> a[i];
      if (a[i] % 2 == 0) {
        ou++;
        x[t1++] = i;
      } else {
        ji++;
        y[t2++] = i;
      }
    }
    if (ou >= 1) {
      cout << 1 << endl;
      cout << x[0] << endl;
    } else if (ji >= 2) {
      cout << 2 << endl;
      cout << y[0] << " " << y[1] << endl;
    } else
      cout << -1 << endl;
  }
  return 0;
}
