#include <bits/stdc++.h>

#include <unistd.h>
 
using namespace std;
 
#define DEBUG(x) cerr<<#x<<": "<<x<<endl;
#define DEBUG_VEC(v) cerr<<#v<<":";for(int i=0;i<v.size();i++) cerr<<" "<<v[i]; cerr<<endl
#define DEBUG_MAT(v) cerr<<#v<<endl;for(int i=0;i<v.size();i++){for(int j=0;j<v[i].size();j++) {cerr<<v[i][j]<<" ";}cerr<<endl;}
 
 
typedef long long ll;
#define int ll
 
#define vi vector<int>
#define vl vector<ll>
#define vii vector< vector<int> >
#define vll vector< vector<ll> >
#define vs vector<string>
#define pii pair<int,int>
#define pis pair<int,string>
#define psi pair<string,int>
#define pll pair<ll,ll>
template<class S, class T> pair<S, T> operator+(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first + t.first, s.second + t.second); }
template<class S, class T> pair<S, T> operator-(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first - t.first, s.second - t.second); }
template<class S, class T> ostream& operator<<(ostream& os, pair<S, T> p) { os << "(" << p.first << ", " << p.second << ")"; return os; }
#define X first
#define Y second
#define rep(i,n) for(int i=0;i<(n);i++)
#define rep1(i,n) for(int i=1;i<=(n);i++)
#define rrep(i,n) for(int i=(n)-1;i>=0;i--)
#define rrep1(i,n) for(int i=(n);i>0;i--)
#define REP(i,a,b) for(int i=a;i<b;i++)
#define in(x, a, b) (a <= x && x < b)
#define all(c) c.begin(),c.end()
template<class T> bool chmax(T &a, const T &b) { if (a<b) { a = b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a = b; return 1; } return 0; }
#define UNIQUE(v) v.erase(std::unique(v.begin(), v.end()), v.end());
const ll inf = 1000000001;
const ll INF = (ll)1e18 + 1;
const ll MOD = 1000000007;
//const ll MOD = 998244353;
const double pi = 3.14159265358979323846;
#define Sp(p) cout<<setprecision(15)<< fixed<<p<<endl;
int dx_ori[4] = { -1,0, 1,0 }, dy_ori[4] = { 0,1,0,-1 };
int dx[4] = {0, 0, 0, 0}, dy[4] = {0, 0, 0, 0};
int dx2[8] = { 1,1,0,-1,-1,-1,0,1 }, dy2[8] = { 0,1,1,1,0,-1,-1,-1 };
#define fio() cin.tie(0); ios::sync_with_stdio(false);
// #define mp make_pair
//#define endl '\n'

ll f(ll k) {
  ll res = 0;
  while (k > 0) {
    res += k % 10;
    k /= 10;
  }
  return res;
}

int query(vi a) {
  cout << "? " << a.size() << endl << flush;
  sort(all(a));
  rep (i, a.size()) {
    cout << a[i];
    if (i != a.size() - 1) {
      cout << " ";
    }
    else {
      cout << endl;
    }
  }
  cout << flush;
  int res;
  cin >> res;
  return res;
}

void answer(vi a) {
  cout << "! " << a.size() << endl << flush;
  sort(all(a));
  rep (i, a.size()) {
    cout << a[i];
    if (i != a.size() - 1) {
      cout << " ";
    }
    else {
      cout << endl;
    }
  }
  cout << flush;
}


signed main() {
  fio();
  int n;
  cin >> n;
  if (n == 2) {
    vi a(2);
    rep (i, 2) a[i] = i + 1;
    answer(a);
    return 0;
  }
  
  set<int> unknown;
  rep1 (i, n) unknown.insert(i);

  vi ans;
  while (unknown.size() > 0) {
    if (unknown.size() + ans.size() == 2) {
      for (auto itr = unknown.begin(); itr != unknown.end(); itr++) {
        ans.push_back(*itr);
      }
      sort(all(ans));
      answer(ans);
      return 0;
    }
    vi b = ans;
    for (auto itr = unknown.begin(); itr != unknown.end(); itr++) {
      b.push_back(*itr);
    }

    int x = b.back();
    b.pop_back();
    int res = query(b);
    if (not res) {
      ans.push_back(x);
    }
    unknown.erase(x);
  }

  sort(all(ans));
  answer(ans);
}