#include <bits/stdc++.h>
using namespace std;
int n;
int ans[1001];
void mark(int st, int mn) {
  for (int i = 1; i <= n; i++) {
    ans[i] = 0;
    if (i >= mn && i != st) ans[i] = 1;
  }
}
int ask(int st, int mn) {
  mark(st, mn);
  int tot = 0, tmp, sum = 0;
  for (int i = 1; i <= n; i++)
    if (ans[i] == 1) tot++;
  printf("%d %d ", 1, tot);
  printf("%d ", st);
  for (int i = 1; i <= n; i++)
    if (ans[i] == 1 && sum != tot)
      printf("%d ", i), sum++;
    else if (ans[i] == 1)
      printf("%d\n", i);
  cout << endl;
  scanf("%d", &tmp);
  return tmp;
}
signed main() {
  int T;
  scanf("%d", &T);
  while (T--) {
    scanf("%d", &n);
    int mx = ask(1, 1);
    int l = 1, r = n + 1;
    while (l + 1 < r) {
      int mid = (l + r) / 2;
      if (ask(1, mid) == mx)
        l = mid;
      else
        r = mid;
    }
    int res = ask(l, 1);
    printf("-1 %d", res);
    cout << endl;
  }
  return 0;
}
