#include <bits/stdc++.h>
using namespace std;
int ask(int v, int l, int r) {
  cout << "1 " << r - l << " " << v;
  for (int i = l; i < r; ++i) cout << " " << i;
  cout << endl;
  int answer;
  cin >> answer;
  if (answer == -1) exit(0);
  return answer;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(NULL);
  int t;
  cin >> t;
  for (int i = 0; i < t; ++i) {
    int n;
    cin >> n;
    const int dist = ask(1, 2, n + 1);
    int l = 2;
    int r = n + 1;
    while (r - l > 1) {
      int m = (l + r) / 2;
      if (ask(1, l, m) == dist)
        r = m;
      else
        l = m;
    }
    cout << "1 " << n - 1 << " " << l;
    for (int i = 1; i <= n; ++i)
      if (i != l) cout << " " << i;
    cout << endl;
    int res;
    cin >> res;
    cout << "-1 " << res << endl;
    cout.flush();
  }
  return 0;
}
