#include<bits/stdc++.h>
#define For(i,a,b) for(register int i=(a);i<=(b);++i)
#define Rep(i,a,b) for(register int i=(a);i>=(b);--i)
using namespace std;
inline int read()
{
	char c=getchar();int x=0;bool f=0;
	for(;!isdigit(c);c=getchar())f^=!(c^45);
	for(;isdigit(c);c=getchar())x=(x<<1)+(x<<3)+(c^48);
	return f?-x:x;
}

#define fi first
#define se second
#define pb push_back
#define mkp make_pair
typedef pair<int,int>pii;
typedef vector<int>vi;

#define maxn 200005
#define inf 0x3f3f3f3f

vector<pii>res;
int n,m;
vi o[maxn];
bool e[2005][2005];

bool chk(int x,int y){
	vi tmp=o[y];
	if(!tmp.size())return 1;
	while(tmp.size()){
		cout<<"? "<<tmp.size()+1<<" "<<x<<" ";
		for(auto t:tmp)cout<<t<<" ";cout<<endl;
		int u,v; cin>>u>>v;
		if(u==-1){
			if(tmp.size()==o[y].size())return 1;
			return 0;
		}
		tmp.erase(find(tmp.begin(),tmp.end(),u^v^x));
		for(auto p:tmp)assert(p!=(u^v^x));
		res.pb(mkp(u,v));
		e[u][v]=e[v][u]=1;
	}return 0;
}

signed main()
{
	cin>>n;
	For(i,1,n){
		int id=0;
		For(j,1,m){
			bool ok=chk(i,j);
			if(!id&&ok)id=j;
		}
		if(!id)++m,id=m;
		o[id].pb(i);
		if(n==2000 && m==4){
			exit(i);
		}
	}
	cout<<"! "<<res.size()<<endl;
	for(auto t:res)cout<<t.fi<<" "<<t.se<<endl;
	return 0;
}