#include <bits/stdc++.h>
using namespace std;
long long gcd(long long a, long long b) {
  if (a % b == 0) return b;
  return gcd(b, a % b);
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie();
  long long a, b, c, d, n, t, m, k;
  cin >> t;
  while (t--) {
    cin >> n;
    vector<long long> res;
    long long v[110];
    long long gg;
    long long sw = 0;
    for (int i = 1; i < n + 1; i++) {
      cin >> v[i];
      if (v[i] % 2 == 0) {
        sw = 1;
        gg = i;
        continue;
      } else {
        res.push_back(i);
      }
    }
    if (sw == 1) {
      cout << 1 << endl;
      cout << gg << endl;
      continue;
    }
    if (res.size() > 1) {
      cout << 2 << endl;
      cout << res[0] << " " << res[1] << endl;
      continue;
    }
    cout << -1 << endl;
  }
}
