/**
 * code generated by JHelper
 * More info: https://github.com/AlexeyDmitriev/JHelper
 * @author aajisaka
 */

#include<bits/stdc++.h>

using namespace std;

void debug_out() { cerr << endl; }
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
  cerr << " " << to_string(H);
  debug_out(T...);
}
#ifdef LOCAL
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif

#define SPEED ios_base::sync_with_stdio(false);cin.tie(nullptr)
#define rep(i,n) for(int i=0; i<(int)(n); i++)
#define all(v) v.begin(), v.end()
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }

using ll = long long;
using P = pair<ll, ll>;

constexpr double PI = 3.14159265358979323846;
mt19937_64 engine(chrono::steady_clock::now().time_since_epoch().count());

class ExplosiveEnergyDrink {
public:

    set<int> ans;

    void solve(istream& cin, ostream& cout) {
      SPEED;
      int n;
#if LOCAL
      n = 4;
      ans.insert(2);
      ans.insert(4);
#else
      cin >> n;
#endif

      set<int> st;
      for(int i=1; i<=n; i++) {
        st.insert(i);
      }
      for(int i=1; i<=n; i++) {
        if (st.size() == 2) break;
        st.erase(i);
        cout << "? " << st.size() << endl;
        for(auto e: st) {
          cout << e << ' ';
        }

        cout << endl;
        int ret = 1;
#if LOCAL
        for(auto e: ans) {
          if (st.find(e) == st.end()) {
            ret = 0;
          }
        }
#else
        cin >> ret;
#endif
        if (ret==0) {
          st.insert(i);
        }
      }

      cout << "! " << st.size() << endl;
      for(auto e: st) {
        cout << e << ' ';
      }
      cout << endl;
    }
};

signed main() {
  ExplosiveEnergyDrink solver;
  std::istream& in(std::cin);
  std::ostream& out(std::cout);
  solver.solve(in, out);
  return 0;
}