#include <cstdio>
#include <algorithm>
#include <vector>
#include <cstring>
#include <queue>
using namespace std;
constexpr int N=2010;
vector<int> ps[N];
vector<pair<int,int>> es;
vector<int> os[N];
int n,d[N],col[N];bool vis[N];
int main(){
	scanf("%d",&n);int c=0;
	for(int i=1;i<=n;++i){
		for(int j=1;j<=c;++j){
			vector<int> qry=ps[j];
			while(qry.size()){
				printf("? %d ",int(qry.size())+1);
				for(int v:qry) printf("%d ",v);printf("%d\n",i);
				fflush(stdout);
				int u,v;scanf("%d%d",&u,&v);
				if(u==-1 && v==-1){
					break;
				}
				es.push_back({u,v});
				os[u].push_back(v);
				os[v].push_back(u);
				qry.erase(find(qry.begin(),qry.end(),u^v^i));
			}
		}
		for(int i=1;i<=c;++i) ps[i].clear();
		memset(d,0,sizeof(d));
		memset(vis,0,sizeof(vis));
		for(auto [u,v]:es) ++d[u],++d[v];
		priority_queue<pair<int,int>,vector<pair<int,int>>,greater<pair<int,int>>> pq;
		for(int j=1;j<=i;++j) pq.push({d[j],j});
		vector<int> seq;
		while(!pq.empty()){
			auto [d0,u]=pq.top();pq.pop();
			if(d0>d[u]) continue;vis[u]=true;seq.push_back(u);
			for(int v:os[u]) if(!vis[v]){
				pq.push({--d[v],v});
			}
		}
		reverse(seq.begin(),seq.end());
		memset(d,0,sizeof(d));
		c=0;
		for(int u:seq){
			vis[u]=false;
			for(int v:os[u]) if(!vis[v]) d[col[v]]=u;
			for(col[u]=1;d[col[u]]==u;++col[u]);
			c=max(c,col[u]);
			ps[col[u]].push_back(u);
		}
	}
	printf("! %d\n",int(es.size()));
	for(auto [u,v]:es) printf("%d %d\n",u,v);
	return 0;
}