#include<iostream>
#include<string>
#include<iomanip>
#include<cmath>
#include<vector>
#include<algorithm>

using namespace std;

#define int long long
#define endl "\n"

constexpr long long INF = (long long)1e18;
constexpr long long MOD = 1'000'000'007; 

string yn(bool f){return f?"Yes":"No";}
string YN(bool f){return f?"YES":"NO";}

int X;

void dfs(int a, int b){
	// cout<<a<<" <> "<<b<<endl;
	if(b-a == 1){
		X = a;
		return ;
	}
	
	if(b-a <= 0) return ;
	
	int m = ((b-a)>>1) + a;
	// cout<<"m = "<<m<<endl;
	cout<<"? "<<m - a<<endl;
	
	for(int i = a; i < m; i++){
		if(i != a) cout<<" ";
		cout<<i;
	}
	
	cout<<endl<<flush;
	
	int ans;
	
	cin>>ans;
	
	if(ans) dfs(a, m);
	else dfs(m, b);
}

signed main(){
	// cin.tie(nullptr);
	// ios::sync_with_stdio(false);
	// cout<<fixed<<setprecision(10);
	
	int N;
	vector<int> ans;
	
	cin>>N;
	
	dfs(1, N+1);
	
	ans.push_back(X);
	
	for(int i = 1; i <= N; i++){
		if(i == X) continue;
		cout<<"? "<<2<<endl;
		if(i < X) cout<<i<<" "<<X<<endl;
		else cout<<X<<" "<<i<<endl;
		cout<<flush;
		
		int a;
		
		cin>>a;
		
		if(a)ans.push_back(i);
	}
	
	sort(ans.begin(), ans.end());
	
	cout<<"! "<<ans.size()<<endl;
	
	for(int i = 0; i < ans.size(); i++){
		if(i) cout<<" ";
		cout<<ans[i];
	}
	cout<<endl;
	cout<<flush;
	return 0;
}