#include <bits/stdc++.h>

using namespace std;

#define FOR(i, a, b) for(int i = (a); i < (b); i++)
#define RFOR(i, a, b) for(int i = (a) - 1; i >= (b); i--)
#define SZ(a) int(a.size())
#define ALL(a) a.begin(), a.end()
#define PB push_back
#define MP make_pair
#define F first
#define S second

typedef long long LL;
typedef vector<int> VI;
typedef pair<int, int> PII;
typedef double db;

const int N = 2'747;
set<int> g[N];
int sz[N];
VI G[N];
int ptr[N];
int p[N];
int pm[N];
bool used[N];
bool inMst[N];
int n = 0;

PII query(int idx)
{
	cout << "> " << idx + 1 << endl;
	int v, d;
	cin >> v >> d;
	n = max(n, v);
	v--;
	return {v, d};
}

void dfs(int v, int t)
{
	//cerr << v << ' ' << par << ' ' << ptr[v] << ' ' << sz[v] << ' ' << SZ(G[v]) << ' ' << p[v] << '\n';

	int cur = v;
	while (ptr[v] < sz[v] || cur != v)
	{
		auto [to, sto] = query(ptr[v]);
		g[v].insert(to);
		sz[to] = sto;
		if (!inMst[to])
		{
			inMst[to] = true;
			G[v].PB(ptr[v]);
			pm[to] = v;
		}
		if (pm[v] == to)
			p[v] = ptr[v];
		ptr[v]++;
		v = to;
	}	
	if (used[v])
	{
		if (p[v] == -1 || t == 0)
			return;
		query(p[v]);
		return;
	}
	used[v] = true;
	for (auto idx : G[v])
	{
		auto [to, sto] = query(idx);
		dfs(to, 1);
	}
	if (p[v] == -1 || t == 0)
		return;
	query(p[v]);
}

void solve()
{
	FOR (i, 0, N)
	{
		g[i].clear();
		G[i].clear();
		p[i] = -1;
		used[i] = false;
		inMst[i] = false;
		sz[i] = 0;
		ptr[i] = 0;
		pm[i] = -1;
	}
	n = 0;
	int v, d;
	cin >> v >> d;
	n = max(n, v);
	v--;
	sz[v] = d;
	inMst[v] = true;
	dfs(v, 0);
	cout << "!";
	FOR (i, 0, n)
	{
		for (auto to : g[i])
			if (to < i)
				cout << ' ' << i + 1 << ' ' << to + 1;
	}
	cout << endl;
	string s;
	cin >> s;
	assert(s == "Correct");
}

int main()
{
	//ios::sync_with_stdio(0);
	//cin.tie(0);
	
	int t;
	cin >> t;
	while (t--)
	{
		solve();
	}
	
	return 0;
}