// -fsanitize=undefined,
//#define _GLIBCXX_DEBUG


#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

#include <iostream>
#include <vector>
#include <string>
#include <map>
#include <set>
#include <queue>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <random>
#include <stdio.h>
#include <fstream>
#include <functional>
#include <cassert>
#include <unordered_map>
#include <bitset>
#include <chrono>




using namespace std;




#define rep(i,n) for (int i=0;i<n;i+=1)
#define rrep(i,n) for (int i=n-1;i>-1;i--)
#define pb push_back
#define all(x) (x).begin(), (x).end()

#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << " )\n";

template<class T>
using vec = vector<T>;
template<class T>
using vvec = vec<vec<T>>;
template<class T>
using vvvec = vec<vvec<T>>;
using ll = long long;
using pii = pair<int,int>;
using pll = pair<ll,ll>;


template<class T>
bool chmin(T &a, T b){
  if (a>b){
    a = b;
    return true;
  }
  return false;
}

template<class T>
bool chmax(T &a, T b){
  if (a<b){
    a = b;
    return true;
  }
  return false;
}

template<class T>
T sum(vec<T> x){
  T res=0;
  for (auto e:x){
    res += e;
  }
  return res;
}

template<class T>
void printv(vec<T> x){
  for (auto e:x){
    cout<<e<<" ";
  }
  cout<<endl;
}



template<class T,class U>
ostream& operator<<(ostream& os, const pair<T,U>& A){
  os << "(" << A.first <<", " << A.second << ")";
  return os;
}

template<class T>
ostream& operator<<(ostream& os, const set<T>& S){
  os << "set{";
  for (auto a:S){
    os << a;
    auto it = S.find(a);
    it++;
    if (it!=S.end()){
      os << ", ";
    }
  }
  os << "}";
  return os;
}

template<class T>
ostream& operator<<(ostream& os, const vec<T>& A){
  os << "[";
  rep(i,A.size()){
    os << A[i];
    if (i!=A.size()-1){
      os << ", ";
    }
  }
  os << "]" ;
  return os;
}

pair<int,int> query(int d){
  cout << "> " << d+1 << endl;
  int nxt_v,nxt_d;
  cin >> nxt_v >> nxt_d;
  return {nxt_v-1,nxt_d};
}

void answer(int N,vec<vec<int>> edges){
  vec<int> ans;
  rep(v,edges.size()){
    for (auto nv:edges[v]){
      assert (nv!=-1);
      if (v < nv){
        ans.push_back(v);
        ans.push_back(nv);
      }
    }
  }

  //cout << Q << " " << 2*N + 2*ans.size() << endl;

  

  cout << "! ";
  rep(i,ans.size()){
    cout << ans[i]+1;
    if (i == int(ans.size())-1){
      cout << endl;
    }
    else{
      cout << " ";
    }
  }

  string judge;
  cin>>judge;
  assert (judge == "Correct");
}


void solve(){
  int x,d;
  cin>>x>>d;
  x--;

  int N = x+1;
  vec<vec<int>> edge(N);
  vec<int> deg(N,-1);
  deg[x] = d;
  edge[x].resize(d,-1);

  vec<int> done(N,0);
  map<pair<int,int>,int> e_to_idx;
  vec<set<int>> need_back(N);
  vec<int> parent(N,-1);

  int pos = x;
  while (true){
    if (done[pos] == deg[pos]){
      if (parent[pos] == -1) break;
      assert (e_to_idx.count({pos,parent[pos]}));
      query(e_to_idx[{pos,parent[pos]}]);
      pos = parent[pos];
      continue;
    }

    auto [nv,nv_d] = query(done[pos]);
    edge[pos][done[pos]] = nv;
    e_to_idx[{pos,nv}] = done[pos];
    done[pos]++;

    if (nv == parent[pos]){
      assert (e_to_idx.count({nv,pos}));
      query(e_to_idx[{nv,pos}]);
      continue;
    }

    if (need_back[pos].count(nv)){
      need_back[pos].erase(nv);
      pos = nv;
      continue;
    }

    if (N < nv+1){
      N = nv + 1;
      edge.resize(N);
      deg.resize(N,-1);
      done.resize(N,0);
      parent.resize(N,-1);
      need_back.resize(N);
    }

    if (deg[nv] == -1){
      deg[nv] = nv_d;
      edge[nv].resize(nv_d);
      parent[nv] = pos;

      pos = nv;
      continue;
    }
    else{
      need_back[nv].insert(pos);
      pos = nv;
      continue;
    }
  }

  
  

  

  answer(N,edge);
  


}

  
  







int main(){
  ios::sync_with_stdio(false);
  std::cin.tie(nullptr);

  
  int T;
  cin>>T;
  while (T--){
    solve();
  }

}