#include <bits/stdc++.h>
using namespace std;
int main() {
  int T;
  cin >> T;
  while (T--) {
    int n, m, ch = 0;
    cin >> n;
    m = n;
    for (int i = 0; i < n; i++) {
      int x;
      cin >> x;
      if (x % 2 == 0) {
        ch = i + 1;
      }
    }
    if (ch)
      cout << 1 << endl << ch << endl;
    else {
      if (n == 1)
        cout << -1 << endl;
      else
        cout << 2 << endl << 1 << " " << 2 << endl;
    }
  }
}
