#include "bits/stdc++.h"
using namespace std;

using ll = long long;
using LL = long long;
using pii = pair<int, int>;

int n;
vector<int> v;
vector<vector<int>> IS;
vector<int> edge[4005];
int asked;

vector<int> ask(vector<int> &v) {
	asked += (int)v.size();
	if (asked > 176000) {
        while (true) {
            asked++;
        }
	}
	cout << "? " << (int)v.size();
	for (auto i : v) {
		cout << " " << i;
	}
	cout << "\n";
	cout.flush();
	vector<int> ans;
	for (int i = 0; i < v.size(); i++) {
		int tmp;
		cin >> tmp;
		ans.push_back(tmp);
	}
	return ans;
}
vector<int> E;
void f(vector<int> &s1, vector<int> &s2, vector<int> &ans) {
	if (!s1.size() || !s2.size()) return;
	if (s2.size() == 1) {
		for (int i = 0; i < s1.size(); i++) {
			int num = ans[i];
			for (int j = 1; j <= num; j++) {
				edge[s1[i]].push_back(s2[0]);
			}
		}
		return;
	}

	vector<int> h1, h2;
	for (int i = 0; i < s2.size(); i++) {
		if (i < s2.size() / 2) h1.push_back(s2[i]);
		else h2.push_back(s2[i]);
	}
    vector<int> q;
    for (auto i : h1) {
        q.push_back(i);
    }
    for (auto i : s1) {
        q.push_back(i);
    }
    auto t = ask(q);
    vector<int> res1, nonzero1;
    int p = 0;
    for (int i = h1.size(); i < h1.size() + s1.size(); i++) {
        ans[p] -= t[i];
        if (t[i] > 0) {
            res1.push_back(t[i]);
            nonzero1.push_back(s1[p]);
        }
        p++;
    }
    f(nonzero1, h1, res1);
    vector<int> res2, nonzero2;
    for (int i = 0; i < ans.size(); i++) {
        if (ans[i] > 0) {
            res2.push_back(ans[i]);
            nonzero2.push_back(s1[i]);
        }
    }
    f(nonzero2, h2, res2);
    return;
}

void solve(int TC) {
	cin >> n;
	asked = 0;
	for (int i = 1; i <= n; i++) {
		v.push_back(i);
	}
	while (v.size() > 1) {
		auto ans = ask(v);
		vector<int> v2, s;
		for (int i = 0; i < v.size(); i++) {
			if (ans[i] == 0) s.push_back(v[i]);
			else v2.push_back(v[i]);
		}
		v = v2;
		IS.push_back(s);
	}
	if (v.size() == 1) {
		IS.push_back(v);
		v.clear();
	}
    srand(time(NULL));
    sort(IS.begin(), IS.end(), [&](vector<int> &x, vector<int> &y) {
        return x.size() < y.size();
    });
    random_shuffle(IS.begin(), IS.end());
	for (int i = 0; i < IS.size(); i++) {
        vector<int> ij;
        int sz = 0;
		for (int j = i + 1; j < IS.size(); j++) {
            vector<int> ij;
            for (auto k : IS[j]) ij.push_back(k);
            sz += IS[j].size();
		}
        for (auto k : IS[i]) ij.push_back(k);
        auto t = ask(ij);
        vector<int> ans;
        for (int k = sz; k < IS[i].size() + sz; k++) {
            ans.push_back(t[k]);
        }
        vector<int> i2, ans2;
        for (int k = 0; k < ans.size(); k++) {
            if (ans[k] > 0) {
                ans2.push_back(ans[k]);
                i2.push_back(IS[i][k]);
            }
        }
        f(i2, IS[j], ans2);
	}
	for (int i = 1; i <= n; i++) {
		vector<int> tmp;
		tmp.push_back(i);
		tmp.push_back(i);
		auto ans = ask(tmp);
		int num = ans[1];
		for (int j = 1; j <= num; j++) {
			edge[i].push_back(i);
		}
	}
	int total = 0;
	for (int i = 1; i <= n; i++) {
		total += edge[i].size();
	}
	cout << "! " << total;
	for (int i = 1; i <= n; i++) {
		for (auto j : edge[i]) {
			cout << " " << i << " " << j;
		}
	}
	cout << "\n";
	cout.flush();
	return;
}

int32_t main() {
	cin.tie(0)->sync_with_stdio(0);
	cout << fixed << setprecision(10);

	int t = 1;
	// cin >> t;

	for (int i = 1; i <= t; i++) {
		solve(i);
	}
}

answer.code: In function ‘void solve(int)’:
answer.code:129:18: error: ‘j’ was not declared in this scope
  129 |         f(i2, IS[j], ans2);
      |                  ^