#include <bits/stdc++.h>
 #define ll long long
 #define ull unsigned long long
 #define pi 3.141592654
 #define NUM 1e18
 #define Mod  1'000'000'007
 #define fixed(n) fixed<<setprecision(n)
 #define cin(v) for(auto &i:v) cin >> i ;
 #define cout(v) for(auto &i:v) cout << i  <<" ";
 #define vowel(x) (x=='e'||x=='a'||x=='i'||x=='o'||x=='u')
 #define small(x) (x>=97&&x<=122)
 #define capital(x) (x>=65&&x<=90)
 #define Tolower(s) transform(s.begin(),s.end(),s.begin(),::tolower);
 #define Toupper(s) transform(s.begin(),s.end(),s.begin(),::toupper);
 #define sz(x) (int)(x.size())
 #define all(v) ((v).begin()), ((v).end())
 #define allr(v) ((v).rbegin()), ((v).rend())
 #define updmax(a,b) a=max(a,b)
 #define updmin(a,b) a=min(a,b)
 #define ceil(a,b) ((a/b)+(a%b?1:0))
 /* asc -> 1 2 3 ,des -> 3 2 1 */
 /***********************************************************************************/
 using namespace std;
 void Rofyda_Elghadban(){
  // #ifndef ONLINE_JUDGE
  //   freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout);
  //  #endif
    ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
 }

 void solve(){
  int n;
  cin>>n;
  vector<int>v(n);
  cin(v);
  int l=0,r=n-1,ans=-1;
  while(l<=r){
    ll sum=0;
    int mid=l+(r-l)/2;
    cout<<"? ";
    cout.flush();
    for(int i=l;i<=mid;i++){
      cout<<v[i]<<" ";
      cout.flush();
    }
    for(int i=l;i<=mid;i++){
      sum+=v[i];
    }
    int x;
    cin>>x;
    if(x==sum){
      l=mid+1;
    }else{
      ans=mid;
      r=mid-1;
    }
  }
  cout<<ans+1<<"\n";
 }

 int main(){
  Rofyda_Elghadban();
  int t;
  cin>>t;
  while(t--){
    solve();
  }
  // solve();
  return 0;
 }