#include <algorithm>
#include <iostream>
#include <cstdlib>
#include <iomanip>
#include <sstream>
#include <cstdio>
#include <bitset>
#include <vector>
#include <queue>
#include <cmath>
#include <stack>
#include <set>
#include <map>

#define ft first
#define sd second
#define pb push_back
#define pf push_front
#define mk make_pair
#define all(c) (c).begin(), (c).end()
#define SWS ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define rfile freopen("input.txt", "r", stdin)
#define wfile freopen("output.txt", "w", stdout)
#define files rfile; wfile
#define DEBUG_VAR(x) #x << " = " << x << ";"
#define DEBUG 1

typedef long long ll;
typedef unsigned long long ull;

using namespace std;

const int Z = 3 * (int)1e5 + 111;
const int INF = (int)1e9 + 111;
const int MODF = (int)1e9 + 7;

int ask(int v, int l, int r) {
  int x;
  cout << 1 << ' ' << r - l + 1 - (v >= l && v <= r) << ' ' << v << ' ';
  for (int i = l; i <= r; i++)
    if (i != v)
      cout << i << ' ';
  cout << endl;
  cin >> x;
  return x;
}

int ans, big;

void find(int v, int l, int r) {
  if (r == l) {
    ans = l;
    return;
  }
  int mid = (l + r) / 2;
  int left_ans = ask(v, l, mid);
  if (left_ans == big) {
    find(v, l, mid);
    return;
  }
  find(v, mid + 1, r);
}

int main() {
  SWS;
  int t;
  cin >> t;
  while (t--) {
    int n;
    cin >> n;
    ans = 0;
    big = ask(1, 2, n);
    find(1, 2, n);
    cout << "-1 " << ask(ans, 1, n) << endl;
  }

  return 0;
}