#include <bits/stdc++.h>
using namespace std;
int a[110];
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int q;
  cin >> q;
  while (q--) {
    int n;
    cin >> n;
    int o = 0, e = 0;
    for (int i = 0; i < n; i++) {
      cin >> a[i];
      if (a[i] & 1)
        o++;
      else
        e++;
    }
    if (e != 0) {
      cout << 1 << endl;
      for (int i = 0; i < n; i++) {
        if (a[i] % 2 == 0) {
          cout << i + 1 << endl;
          break;
        }
      }
    } else if (o >= 2) {
      int s[2];
      int k = 0;
      for (int i = 0; i < n; i++) {
        if (a[i] & 1) {
          s[k] = i;
          k++;
          if (k == 2) break;
        }
      }
      cout << k << endl;
      cout << s[0] + 1 << " " << s[1] + 1 << endl;
    } else {
      cout << -1 << endl;
    }
  }
  return 0;
}
