#include <bits/stdc++.h>
using namespace std;
void c_p_c() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cin.tie(0);
}
int main() {
  c_p_c();
  int Q;
  cin >> Q;
  while (Q--) {
    int n, h = 0, j = 0, b[2];
    cin >> n;
    for (int i = 1; i <= n; i++) {
      int a;
      cin >> a;
      if (a % 2 == 0)
        h = i;
      else {
        if (j == 2) continue;
        b[j++] = i;
      }
    }
    if (h > 0)
      cout << "1\n" << h << "\n";
    else if (j == 2) {
      cout << "2\n" << b[0] << " " << b[1] << "\n";
    } else
      cout << "-1\n";
  }
}
