// what is matter? never mind. 
#include<bits/stdc++.h>
#define For(i,a,b) for(int i=(a);i<=(b);++i)
#define Rep(i,a,b) for(int i=(a);i>=(b);--i)
#define ll long long
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);
	if(f)x=-x;return 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 2000005
#define inf 0x3f3f3f3f

int n,k,m;

int deg[maxn];
bool e[2005][2005];
vi o[maxn];
vector<pii>res;

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;
		++deg[u],++deg[v];
	}
	return 0;
}

int p[maxn];
int col[maxn];
bool vis[maxn];
void build(int n){
	For(i,1,n)p[i]=i;
	sort(p+1,p+n+1,[&](int x,int y){
		return deg[x]>deg[y];
	});
	For(i,1,m) o[i].clear();
	m=0;
	For(i,1,n){
		int u=p[i];
		For(j,1,i-1) if(e[u][p[j]]) vis[col[j]]=1;
		col[i]=1;
		while(vis[col[i]])++col[i];
		For(j,1,i-1) if(e[u][p[j]]) vis[col[j]]=0;
		m=max(m,col[i]);
		o[col[i]].pb(u);
	}
}

signed main()
{
	cin>>n;
	For(i,2,n){
		build(i-1);
		For(j,1,m) chk(i,j);
	}
	int mx=*max_element(deg+1,deg+n+1);
	assert(m<=mx+1);
	cout<<"! "<<res.size()<<endl;
	for(auto t:res)cout<<t.fi<<" "<<t.se<<endl;
	return 0;
}
/*
1 2
1 3
1 4
2 5
4 5
1 4
*/