#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define pii pair<int, int>
#define mp make_pair
#define fi first
#define se second 
#define deb(var) cerr << #var << '=' << var << "; "
#define int long long
int n, tot;
set<int> sub[2010], tmp; vector<pii> g;
signed main() {
	cin >> n;
	tot = 1; sub[1].insert(1);
	for (int i = 2; i <= n; i++) {
		int ok = 0;
		for (int j = 1; j <= tot; j++) {
			cout << "? " << sub[j].size() + 1 << " " << i << " ";
			tmp = sub[j];
			for (set<int>::iterator it = tmp.begin(); it != tmp.end(); it++) cout << *it << " "; cout << endl;
			int u, v;
			cin >> u >> v;
			if (u != i) swap(u, v);
			if (u == -1 && v == -1) ok = j;
			else {
				g.pb(mp(u, v));
				while (true) {
					tmp.erase(v);
					if (tmp.empty()) break;
					cout << "? " << tmp.size() + 1 << " " << i << " ";
					for (set<int>::iterator it = tmp.begin(); it != tmp.end(); it++) cout << *it << " "; cout << endl;
					cin >> u >> v;
					if (u != i) swap(u, v); 
					if (v != -1) {
						g.pb(mp(u, v));
					} else break;
				}
			}
		}
		if (ok) sub[ok].insert(i); else sub[++tot].insert(i);
	}
	cout << "! " << g.size() << endl;
	for (int i = 0; i < g.size(); i++) cout << g[i].fi << " " << g[i].se << endl;
	return 0;
}