#include <bits/stdc++.h>
using namespace std;
const int maxn = 100 + 5;
int t, n, a[maxn];
vector<int> o;
int main() {
  cin >> t;
  while (t--) {
    o.clear();
    cin >> n;
    for (int i = 0; i < n; i++) cin >> a[i];
    bool ok = 0;
    for (int i = 0; !ok && i < n; i++) {
      if (a[i] % 2 == 1) {
        o.push_back(i + 1);
        if (o.size() == 2) {
          cout << 2 << endl;
          cout << o[0] << " " << o[1] << endl;
          ok = 1;
        }
      } else {
        cout << 1 << endl;
        cout << i + 1 << endl;
        ok = 1;
      }
    }
    if (!ok) cout << -1 << endl;
  }
}
