#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define fi first
#define se second
const ll mod=998244353;
int n,m;
int deg[2505];
vector<int>adj[2505];
bool vis[2505];
int e[2505][2505];
void dfs(int id,int p){
	//cout << "dfs " << id << ' ' << p << ' ' << e[id][p] << endl;
	int x=id;
	while(adj[x].size()<deg[x]){
		cout << "> " << adj[x].size()+1 << endl;
		int nx;cin >> nx;cin >> deg[nx];
		n=max(n,nx);
		e[x][nx]=adj[x].size()+1;
		adj[x].push_back(nx);
		x=nx;
	}
	vis[x]=true;
	for(auto c:adj[x]){
		if(!vis[c]){
			cout << "> " << e[x][c] << endl;
			int aespa,winter;cin >> aespa >> winter;
			dfs(c,x);
		}
	}
	if(p==0) return;
	cout << "> " << e[x][p] << endl;
	int aespa,winter;cin >> aespa >> winter;
}
void solve(){
	int x;
	cin >> x;cin >> deg[x];
	n=x;
	dfs(x,0);
	vector<pair<int,int> >ans;
	for(int i=1; i<=n ;i++){
		for(auto c:adj[i]){
			if(c>i) ans.push_back({i,c});
		}
	}
	cout << "! ";
	for(auto c:ans) cout << c.fi << ' ' << c.se << ' ';
	cout << endl;
	string ver;cin >> ver;
	if(ver[0]=='W') exit(0);
	for(int i=1; i<=n ;i++){
		adj[i].clear();
		vis[i]=false;
	}
}
int main(){
	ios::sync_with_stdio(false);
	int t;cin >> t;while(t--) solve();
}