#include <cassert>
#include <cmath>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <functional>
#include <iostream>
#include <limits>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;

using Int = long long;

template <class T1, class T2> ostream &operator<<(ostream &os, const pair<T1, T2> &a) { return os << "(" << a.first << ", " << a.second << ")"; };
template <class T> ostream &operator<<(ostream &os, const vector<T> &as) { const int sz = as.size(); os << "["; for (int i = 0; i < sz; ++i) { if (i >= 256) { os << ", ..."; break; } if (i > 0) { os << ", "; } os << as[i]; } return os << "]"; }
template <class T> void pv(T a, T b) { for (T i = a; i != b; ++i) cerr << *i << " "; cerr << endl; }
template <class T> bool chmin(T &t, const T &f) { if (t > f) { t = f; return true; } return false; }
template <class T> bool chmax(T &t, const T &f) { if (t < f) { t = f; return true; } return false; }
#define COLOR(s) ("\x1b[" s "m")


constexpr int MAX_N = 2505;

int deg[MAX_N];
vector<int> to[MAX_N];
bool vis[MAX_N];

void init() {
  for (int u = 0; u < MAX_N; ++u) {
    deg[u] = -1;
    to[u].clear();
    vis[u] = 0;
  }
}

int cur;
void rd() {
  int d;
  scanf("%d%d", &cur, &d);
  --cur;
  deg[cur] = d;
}
void ask(int j) {
  assert(0 <= j); assert(j < deg[cur]);
  printf("> %d\n", j + 1);
  fflush(stdout);
  rd();
}

void dfs(int u) {
  assert(cur == u);
  if ((int)to[u].size() < deg[u]) {
    ask(to[u].size());
    const int v = cur;
    to[u].push_back(v);
    dfs(v);
  } else {
    // grow DFS tree
    if (!vis[u]) {
      vis[u] = 1;
      for (int j = 0; j < deg[u]; ++j) {
        const int v = to[u][j];
        if (!vis[v]) {
          ask(j);
          dfs(v);
          assert(cur == v);
          for (int k = 0; k < (int)to[v].size(); ++k) if (to[v][k] == u) {
            ask(k);
            break;
          }
          assert(cur == u);
        }
      }
    }
  }
}

int main() {
  int numCases;
  scanf("%d", &numCases);
  for (int caseId = 0; caseId < numCases; ++caseId) {
    init();
    rd();
    dfs(cur);
    printf("!");
    for (int u = 0; ~deg[u]; ++u) {
      for (const int v : to[u]) if (u < v) {
        printf(" %d %d", u + 1, v + 1);
      }
    }
    puts("");
    fflush(stdout);
    scanf("%*s");
  }
  return 0;
}