#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
/* run this program using the console pauser or add your own getch, system("pause") or input loop */


void Print(int l, int r){
	for (int i = l; i <= r; ++i)
		cout << " " << i;
	cout << endl;
}
void PrintExcept(int l, int r, int exc){
	for (int i = l; i <= r; ++i){
		if (i != exc)
		cout << " " << i;
	}
	cout << endl;
}

int main(int argc, char** argv) {
	int n_t, n;
	int l, r, f;
	int curr1, curr2, Max;
	cin >> n_t;
	for (int i = 0; i < n_t; ++i){
		cin >> n;
		l = 2;
		r = n;
		f = r;
		cout << "1 " << (n - 1) << " 1";
		Print(l, r);
		cin >> Max; if (Max == -1) return 0;
		//r = n/2 + 1;
		while (l != r){
			f = r;
			cout << l << " " << r << "\n";
			cout << "1 " << (r - l)/2 + 1 << " 1";
			Print(l, (r - l)/2 + l);
			cin >> curr1; if (curr1 == -1) return 0;
			if (curr1 < Max){
				l = (r - l)/2 + l + 1;
				r = n;
			}else
				r = (r - l)/2 + l;
			if (curr1 > Max) Max = curr1;
		}
		cout << "1 " << (n - 1) << " " << f;
		PrintExcept(1, n, f);
		cin >> curr1; if (curr1 == -1) return 0;
		cout << "-1 " << max (curr1, Max) << endl;
	}


	return 0;
}