#include <bits/stdc++.h>
using namespace std;
int a[110];
int main() {
  int t;
  cin >> t;
  while (t--) {
    int n;
    cin >> n;
    int x = 0;
    bool flag = 0;
    for (int i = 0; i < n; i++) {
      cin >> a[i];
      if (a[i] % 2 == 0)
        flag = 1;
      else
        x++;
    }
    if (flag) {
      cout << 1 << endl;
      for (int i = 0; i < n; i++) {
        if (a[i] % 2 == 0) {
          cout << i + 1 << endl;
          break;
        }
      }
    } else if (!flag && x >= 2) {
      cout << 2 << endl;
      x = 2;
      for (int i = 0; i < n && x > 0; i++) {
        if (a[i] % 2) {
          cout << i + 1 << " ";
          x--;
        }
      }
      cout << endl;
    } else
      cout << -1 << endl;
  }
  return 0;
}
