#include <bits/stdc++.h>
using namespace std;
int a[105];
int main() {
  int T;
  cin >> T;
  while (T--) {
    memset(a, 0, sizeof(a));
    int n;
    cin >> n;
    int index = 0;
    for (int i = 0; i < n; i++) cin >> a[i];
    if (n == 1 && a[0] % 2 == 1) {
      cout << "-1" << endl;
      continue;
    }
    for (int i = 0; i < n; i++) {
      if (a[i] % 2 == 0) {
        index = i + 1;
        break;
      }
    }
    if (index == 0)
      cout << "2" << endl << "1 2" << endl;
    else
      cout << "1" << endl << index << endl;
  }
  return 0;
}
