#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, k, t;
  vector<int> x;
  cin >> n;
  for (int i = 0; i < n; ++i) {
    int flag = 0;
    cin >> k;
    if (k == 0) {
      cout << -1 << endl;
      continue;
    } else {
      for (int j = 0; j < k; ++j) {
        cin >> t;
        x.push_back(t % 2);
      }
      for (int l = 0; l < x.size(); ++l) {
        if (x[l] == 0) {
          cout << 1 << endl;
          cout << l + 1 << endl;
          flag = 1;
          break;
        } else {
          if (l + 1 < x.size()) {
            if (x[l + 1] == 1) {
              cout << 2 << endl;
              cout << l + 1 << " " << l + 2 << endl;
              flag = 1;
              break;
            }
          }
        }
      }
      if (flag == 0) cout << -1 << endl;
    }
    x.clear();
  }
  return 0;
}
