int query(int a,int b){
	puts("? 1 1");
	enter(a);
	enter(b);
	fflush(stdout);
	int t;scanf("%d",&t);
	return t;
}
int query(int pos,int lef,int rig){
	printf("? 1 %d\n",rig-lef+1);
	enter(pos);
	_rep(i,lef,rig)space(i);
	puts("");
	fflush(stdout);
	int t;scanf("%d",&t);
	return t;
}
int solve(int pos,int lef,int rig){
	int mid=lef+rig>>1;
	if(lef==rig)return mid;
	int t=query(pos,lef,mid);
	if(t)return solve(pos,lef,mid);
	else
	return solve(pos,mid+1,rig);
}
int main()
{
	int T=read_int();
	while(T--){
		int n;scanf("%d",&n);
		vector<int> ans;
		int pos=2;
		while((query(pos,1,pos-1))==0)pos++;
		int t=solve(pos,1,pos-1);
		_for(i,1,pos){
			if(i!=t)
			ans.push_back(i);
		}
		_rep(i,pos+1,n){
			if(query(pos,i)==0)
			ans.push_back(i);
		}
		printf("! %d ",ans.size());
		_for(i,0,ans.size())space(ans[i]);
		puts("");
		fflush(stdout);
	}
	return 0;
}