#include <bits/stdc++.h>
using namespace std;
int main() {
  int t;
  cin >> t;
  while (t--) {
    int n, a[105], flag = 0, m = 0;
    cin >> n;
    for (int i = 0; i < n; i++) {
      cin >> a[i];
      if (a[i] % 2 == 0) {
        flag = 1;
        m = i + 1;
      }
    }
    if (flag == 1)
      cout << 1 << "\n" << m << "\n";
    else if (n == 1 && flag == 0)
      cout << "-1\n";
    else if (flag == 0) {
      cout << 2 << "\n"
           << "1 2"
           << "\n";
    }
  }
  return 0;
}
