/**
 * @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::set<int> &s) {
  cout << "? " << 1 + (int)s.size() << ' ';
  for (int i : s)
    cout << i + 1 << ' ';
  cout << v + 1 << std::endl;

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

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::set<int>> v;
  v.push_back({0});
  std::vector<std::pair<int, int>> ans;
  for (int i = 1; i < n; ++i) {
    int ind = -1;
    for (int j = 0; j < (int)v.size(); ++j) {
      std::set<int> s = v[j];
      // auto [a, b] = query(i, s);
      int a, b;
      std::tie(a, b) = query(i, s);
      if (a == -1)
        ind = j;
      while (a != -1) {
        if (a > b)
          std::swap(a, b);
        ans.emplace_back(a, b);
        s.erase(a);
        std::tie(a, b) = query(i, s);
      }
    }
    if (ind == -1)
      v.push_back({i});
    else
      v[ind].insert(i);
  }
  cout << "! " << (int)ans.size() << std::endl;
  for (auto [a, b] : ans)
    cout << a + 1 << ' ' << b + 1 << std::endl;
}