#include <bits/stdc++.h>
using namespace std;
void solve() {
  long long int n;
  cin >> n;
  long long int a[n];
  vector<long long int> v;
  for (long long int i = 0; i < n; i++) {
    cin >> a[i];
  }
  for (long long int i = 0; i < n; i++) {
    if (!(a[i] & 1)) {
      cout << 1 << '\n';
      cout << i + 1 << '\n';
      return;
    } else {
      v.push_back(i + 1);
      if (!(v.size() & 1)) {
        cout << v.size() << '\n';
        for (auto c : v) cout << c << " ";
        cout << '\n';
        v.clear();
        return;
      }
    }
  }
  cout << -1 << '\n';
}
int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long int t;
  cin >> t;
  while (t--) solve();
  return 0;
}
