#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;


vector<int> ans;

bool check(int num){
	
	cout<<"? "<<num + ans.size()<<endl;
	cout<<flush;
	
	bool flag = false;
	for(int i = 0; i < num; i++){
		if(i) cout<<" ";
		cout<<i+1;
		cout<<flush;
		flag = true;
	}
	cout<<" | ";
	for(int i = 0; i < ans.size(); i++){
		if(flag) cout<<" ";
		cout<<ans[i];
		flag = true;
	}
	cout<<endl;
	cout<<flush;
	
	int ans;
	
	cin>>ans;
	
	return ans;
}

signed main(){
	// cin.tie(nullptr);
	// ios::sync_with_stdio(false);
	// cout<<fixed<<setprecision(10);
	
	int N;
	
	cin>>N;
	
	while(true){
		bool flag = false;
		int l = 0, h = N+1, m;
		
		sort(ans.begin(), ans.end());
		
		if(l+1>=h) break;
		// cout<<"l = "<<l<<" h = "<<h<<endl;
		while(l+1 < h){
			m = (l+h)>>1;
			
			// if(m == 1){
				// flag = true;
			// }
			// cout<<"l = "<<l<<" "<<"m = "<<m<<" h = "<<h<<endl;
			if(check(m)){
				h = m;
			} else {
				l = m;
			}
		}
		
		N = h-1;
		
		ans.push_back(h);
		
		// if(flag) break;
	}
	
	
	
	sort(ans.begin(), ans.end());
	
	cout<<"! "<<ans.size()<<endl;
	
	for(int i = 0; i < ans.size(); i++){
		if(i) cout<<" ";
		cout<<ans[i];
		cout<<flush;
	}
	cout<<endl;
	
	cout<<flush;
	return 0;
}