#include <iostream>
#include <vector>
#include <algorithm>
#include <array>
#include <random>
#include <chrono>

using namespace std;
using i64 = long long;
using u64 = unsigned long long;

mt19937_64 rng {std::chrono::steady_clock::now().time_since_epoch().count()};

int q(vector<int>& vis, int x) {
	int cnt = 0;
	for(int i = 1; i <= x; i++) 
		cnt += (vis[i] == 0);
	cout << "? " << cnt << " ";
	for(int i = 1; i <= x; i++)
		if(!vis[i])
			cout << i << " ";
	cout << endl;
	int r1, r2;
	cin >> r1 >> r2;
	if(r1 == -1)
		return r1;
	return r1 + r2 - x;
}

void solve() {
	int n;
	cin >> n;
	vector<array<int, 2>> ans;
	for(int i = 1; i <= n; i++) {
		vector<int> vis(n + 1, 0);
		int now = q(vis, i);
		while(now != -1) {
			vis[now] = 1;
			ans.push_back({now, i});
			now = q(vis, i);
		}
	}
	cout << "! " << ans.size() << endl;
	for(auto x : ans)
		cout << x[0] << ' ' << x[1] << endl; 

}

int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	int t = 1;
	//cin >> t;
	while(t--) {
		solve();
	}
}