#include <bits/stdc++.h>
using namespace std;
int main() {
  int t;
  cin >> t;
  while (t--) {
    int n;
    cin >> n;
    int A[n];
    int k = -1;
    for (int i = 0; i < n; i++) {
      cin >> A[i];
      if (A[i] % 2 == 0) {
        k = i;
      }
    }
    if (k != -1) {
      cout << 1 << "\n" << k + 1 << "\n";
    } else {
      if (n == 1) {
        cout << -1 << "\n";
      } else {
        cout << 2 << "\n" << 1 << " " << 2 << "\n";
      }
    }
  }
}
