#include <bits/stdc++.h>
int n, ans, Test_num;
int a[102];
int main() {
  scanf("%d", &Test_num);
  while (Test_num--) {
    ans = 0;
    scanf("%d", &n);
    for (int i = 1; i <= n; i++) scanf("%d", &a[i]);
    for (int i = 1; i <= n; i++)
      if (!(a[i] & 1)) {
        ans = i;
        break;
      }
    if (ans)
      printf("1\n%d\n", ans);
    else {
      if (n == 1)
        puts("-1");
      else
        printf("2\n1 2\n");
    }
  }
  return 0;
}
