#include <bits/stdc++.h>
using namespace std;
const int N = 102;
int test, n, a[N];
void Solve() {
  for (int i = 1; i <= n; ++i)
    if (a[i] % 2 == 0) {
      cout << "1\n";
      cout << i << "\n";
      return;
    }
  if (n < 2) {
    cout << "-1\n";
    return;
  }
  cout << "2\n1 2\n";
}
int main() {
  cin >> test;
  while (test--) {
    cin >> n;
    for (int i = 1; i <= n; ++i) cin >> a[i];
    Solve();
  }
  return 0;
}
