#include <bits/stdc++.h>
using namespace std;
int main() {
  long long t;
  cin >> t;
  while (t--) {
    long long n;
    cin >> n;
    long long x;
    long long ans = -1;
    long long count = 0;
    long long o1, o2;
    long long a[n];
    for (long long i = 0; i < n; i++) {
      cin >> a[i];
    }
    for (long long i = 0; i < n; i++) {
      x = a[i];
      if (x % 2 == 0) {
        ans = i;
        break;
      } else if (count == 0) {
        o1 = i;
        count++;
      } else if (count == 1) {
        o2 = i;
        count++;
        ans = -2;
        break;
      }
    }
    if (ans == -1) {
      cout << -1 << endl;
    } else {
      if (count < 2) {
        cout << 1 << endl;
        cout << ans + 1 << endl;
      } else {
        cout << 2 << endl;
        cout << o1 + 1 << " " << o2 + 1 << endl;
      }
    }
  }
}
