#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  for (int i{0}; i < n; i++) {
    int found{0};
    int num{};
    cin >> num;
    int res{};
    for (int j{0}; j < num; j++) {
      int numI;
      cin >> numI;
      if (numI % 2 == 0) {
        found = 1;
        res = j + 1;
      }
    }
    if (found == 1) {
      cout << 1 << '\n' << res << '\n';
    } else {
      if (num > 1)
        cout << 2 << '\n' << 1 << ' ' << 2 << '\n';
      else
        cout << -1 << '\n';
    }
  }
  return 0;
}
