#include <bits/stdc++.h>
using namespace std;
class TaskA {
 public:
  void solve(std::istream& in, std::ostream& out) {
    int t = 1;
    in >> t;
    while (t--) {
      int n;
      in >> n;
      vector<int> v(n);
      for (int i = 0; i < n; ++i) {
        in >> v[i];
      }
      bool ok = false;
      for (int i = 0; i < n; ++i) {
        if (v[i] % 2 == 0) {
          out << "1\n" << i + 1 << endl;
          ok = true;
          break;
        }
      }
      if (ok) continue;
      if (n >= 2)
        out << "2\n"
            << "1 2" << endl;
      else
        out << -1 << endl;
    }
  }
};
int main() {
  TaskA solver;
  std::istream& in(std::cin);
  std::ostream& out(std::cout);
  solver.solve(in, out);
  return 0;
}
