#include <bits/stdc++.h>
const int maxn = 1e2 + 7;
const long long mod = 998244353;
const int INF = 0x3f3f3f3f;
const double PI = acos(-1);
const double EPS = 1e-6;
const int dx[] = {0, 0, -1, 1};
const int dy[] = {-1, 1, 0, 0};
using namespace std;
int n, t;
int a[maxn];
int main() {
  scanf("%d", &t);
  while (t--) {
    int ans = -1;
    scanf("%d", &n);
    for (int i = 1; i <= n; ++i) {
      scanf("%d", &a[i]);
      if (a[i] % 2 == 0) ans = i;
    }
    if (n == 1 && a[1] % 2) {
      printf("-1\n");
      continue;
    }
    if (ans != -1)
      printf("1\n%d\n", ans);
    else
      printf("2\n1 2\n");
  }
}
