#include <bits/stdc++.h>
using namespace std;
int main() {
  int t;
  cin >> t;
  while (t--) {
    int n;
    cin >> n;
    int a[n];
    for (int i = 0; i < n; i++) {
      cin >> a[i];
    }
    int p = 0, k = 0;
    int b[2];
    for (int i = 0; i < n; i++) {
      if (a[i] % 2 == 0) {
        k++;
        cout << "1" << endl;
        cout << i + 1 << endl;
        break;
      }
      if (a[i] % 2 != 0) {
        p++;
        b[p - 1] = i + 1;
        if (p == 2) {
          cout << p << endl;
          cout << b[0] << " " << b[1] << endl;
          break;
        }
      }
    }
    if (p < 2 && k == 0) {
      cout << "-1" << endl;
    }
  }
}
