#include <bits/stdc++.h>
using namespace std;
int main() {
  int t;
  cin >> t;
  int ta = 0;
  int n;
  int a[101];
  int ans[101][3];
  int count = 0;
  while (t--) {
    cin >> n;
    count = 0;
    ans[ta][0] = -1;
    for (int i = 0; i < n; i++) {
      cin >> a[i];
    }
    for (int i = 0; i < n; i++) {
      if (a[i] % 2 == 0) {
        ans[ta][0] = 1;
        ans[ta][1] = i + 1;
        break;
      } else {
        count++;
        if (count == 1) {
          ans[ta][1] = i + 1;
        }
        if (count == 2) {
          ans[ta][0] = 2;
          ans[ta][2] = i + 1;
          break;
        }
      }
    }
    ta++;
  }
  for (int i = 0; i < ta; i++) {
    if (ans[i][0] == -1) {
      cout << ans[i][0] << endl;
    }
    if (ans[i][0] == 1) {
      cout << ans[i][0] << endl;
      cout << ans[i][1] << endl;
    }
    if (ans[i][0] == 2) {
      cout << ans[i][0] << endl;
      cout << ans[i][1] << " ";
      cout << ans[i][2] << endl;
    }
  }
  return 0;
}
