#include <bits/stdc++.h>
using namespace std;
const int MOD = (int)1e9 + 7;
const int INF = (int)1e9;
const long long LINF = (long long)1e18;
const long double PI = acos((long double)-1);
const long double EPS = 1e-9;
long long gcd(long long a, long long b) {
  if (a < b) swap(a, b);
  long long r;
  while (b) {
    r = a % b;
    a = b;
    b = r;
  }
  return a;
}
long long lcm(long long a, long long b) { return a / gcd(a, b) * b; }
long long fpow(long long n, long long k, int p = MOD) {
  long long r = 1;
  for (; k; k >>= 1) {
    if (k & 1) r = r * n % p;
    n = n * n % p;
  }
  return r;
}
template <class T>
void setmin(T& a, T val) {
  if (a > val) a = val;
}
template <class T>
void setmax(T& a, T val) {
  if (a < val) a = val;
}
void addmod(int& a, int val, int p = MOD) {
  if ((a = (a + val)) >= p) a -= p;
}
void submod(int& a, int val, int p = MOD) {
  if ((a = (a - val)) < 0) a += p;
}
int mult(int a, int b, int p = MOD) { return (long long)a * b % p; }
int inv(int a, int p = MOD) { return fpow(a, p - 2, p); }
const int N = 15;
vector<pair<long long, long long> > a[N];
void build(int s, int e, int d) {
  a[d].push_back(make_pair(s, e));
  if (s == e) return;
  int mid = (s + e) / 2;
  build(s, mid, d + 1);
  build(mid + 1, e, d + 1);
}
int main() {
  ios::sync_with_stdio(false);
  cout.tie(0);
  cin.tie(0);
  int t;
  cin >> t;
  while (t--) {
    int n;
    cin >> n;
    for (int i = 0; i < 15; i++) a[i].clear();
    build(1, n, 0);
    int ans = 0;
    vector<int> v1, v2;
    for (int i = 1; i <= n; i++) {
      v1.clear();
      v2.clear();
      if (a[i].size() == 0)
        break;
      else {
        for (int j = 0; j < a[i].size(); j++) {
          if (j % 2) {
            for (int k = a[i][j].first; k <= a[i][j].second; k++)
              v2.push_back(k);
          } else {
            for (int k = a[i][j].first; k <= a[i][j].second; k++)
              v1.push_back(k);
          }
        }
      }
      cout << v1.size() << " " << v2.size() << " ";
      for (int i = 0; i < v1.size(); i++) cout << v1[i] << " ";
      for (int i = 0; i < v2.size(); i++) cout << v2[i] << " ";
      cout << "\n";
      cout.flush();
      int val;
      cin >> val;
      ans = max(ans, val);
    }
    cout << "-1 " << ans << "\n";
    cout.flush();
  }
  return 0;
}
