/**
 * @file qoj4218-1.cpp
 * @author n685
 * @brief
 * @date 2023-08-26
 *
 *
 */
#include <bits/stdc++.h>

#ifdef LOCAL
using std::cerr;
using std::cin;
using std::cout;
#else
using std::cin;
using std::cout;
#define cerr                                                                   \
  if (false)                                                                   \
  std::cerr
#endif

#ifdef LOCAL
#include "dd/debug.h"
#define dbg(...) lineInfo(__LINE__, #__VA_ARGS__), dbg1(__VA_ARGS__)
#define dbgR(...) lineInfo(__LINE__, #__VA_ARGS__), dbg2(__VA_ARGS__)
#define dbgP(p, ...)                                                           \
  lineInfo(__LINE__, #__VA_ARGS__ " proj"), dbg3(p, __VA_ARGS__)
#define dbgRP(p, ...)                                                          \
  lineInfo(__LINE__, #__VA_ARGS__ " proj"), dbg4(p, __VA_ARGS__)
void nline() { cerr << '\n'; }
#else
#define dbg(...) 42
#define dbgR(...) 4242
#define dbgP(...) 420
#define dbgRP(...) 420420
void nline() {}
#endif

std::pair<int, int> query(int v, const std::vector<int> &s,
                          const std::vector<bool> &vis) {
  // cout << "? " << 1 + (int)s.size() << ' ';
  int num = 1;
  for (int i : s)
    if (!vis[i])
      num++;
  cout << "? " << num << ' ';
  for (int i : s)
    if (!vis[i])
      cout << i + 1 << ' ';
  cout << v + 1 << std::endl;

  int a, b;
  cin >> a >> b;
  if (a != -1)
    a--, b--;
  return {a, b};
}

template <class T> struct Seg {
  static const T ID;
  T comb(T a, T b) {
    if (a == ID)
      return b;
    else if (b == ID)
      return a;
    else
      return (deg[a] < deg[b]) ? a : b;
  }
  int sz = 0;
  std::vector<T> &deg;
  std::vector<T> val;

  Seg(std::vector<T> &v) : deg(v) {
    sz = (int)v.size();
    val.resize(2 * sz);
    std::iota(val.begin() + sz, val.end(), 0);
    build();
  }
  void build() {
    for (int i = sz - 1; i >= 1; --i)
      val[i] = comb(val[2 * i], val[2 * i + 1]);
  }
  void upd(int ind) {
    // f(val[ind += sz]);
    deg[ind]--;
    ind += sz;
    for (ind /= 2; ind >= 1; ind /= 2)
      val[ind] = comb(val[2 * ind], val[2 * ind + 1]);
  }
  void set(int ind) {
    deg[ind] = (int)1e9;
    ind += sz;
    for (ind /= 2; ind >= 1; ind /= 2)
      val[ind] = comb(val[2 * ind], val[2 * ind + 1]);
  }
  T query() { return val[1]; }
};
template <class T> const T Seg<T>::ID = -1;

int main() {
#ifdef LOCAL

#else
  // cin.tie(nullptr)->sync_with_stdio(false);
  std::ios::sync_with_stdio(false);
#endif

  int n;
  cin >> n;

  std::vector<std::vector<int>> v;
  v.push_back({0});
  std::vector<std::pair<int, int>> ans;
  std::vector<std::vector<int>> adj(n);

  for (int i = 1; i < n; ++i) {
    int ind = -1;
    v.clear();
    std::vector<bool> vis(n);
    {
      std::vector<int> deg(i);
      std::transform(adj.begin(), adj.begin() + i, deg.begin(),
                     [](const auto &a) { return (int)a.size(); });
      Seg<int> seg(deg);
      std::vector<int> seq;
      for (int j = 0; j < i; ++j) {
        int node = seg.query();
        for (int k : adj[node])
          seg.upd(k);
        seg.set(node);
        seq.push_back(node);
      }
      std::vector<int> c(i, -1);
      for (int j : seq | std::views::reverse) {
        int cc = 0;
        std::vector<bool> freq(adj[j].size() + 1);
        for (int k : adj[j]) {
          if (c[k] == -1)
            continue;
          if (c[k] <= adj[j].size())
            freq[c[k]] = true;
        }
        for (int k = 0; k <= (int)adj[j].size(); ++k) {
          if (!freq[k]) {
            c[j] = k;
            if ((int)v.size() <= k)
              v.resize(k + 1);
            v[k].push_back(j);
            break;
          }
        }
      }
    }
    for (int j = 0; j < (int)v.size(); ++j) {
      std::vector<int> s = v[j];
      // auto [a, b] = query(i, s);
      int a, b;
      std::tie(a, b) = query(i, s, vis);
      if (a == -1)
        ind = j;
      while (a != -1) {
        if (a > b)
          std::swap(a, b);
        assert(b == i);
        ans.emplace_back(a, b);
        adj[a].push_back(b);
        adj[b].push_back(a);
        // s.erase(a);
        vis[a] = true;
        std::tie(a, b) = query(i, s, vis);
      }
    }
    if (ind == -1)
      v.push_back({i});
    else
      v[ind].push_back(i);
    dbg(v);
  }
  cout << "! " << (int)ans.size() << std::endl;
  for (auto [a, b] : ans)
    cout << a + 1 << ' ' << b + 1 << std::endl;
}