#include <bits/stdc++.h>
#define rep1(i, l, r) for (int i = l; i <= int(r); ++i)
#define rep2(i, l, r) for (int i = l; i >= int(r); --i)
#define rer(i, l, r, a) rep1(i, l, r) read(a[i])
#define ptc putchar
#define il inline
#define eb emplace_back
#define ef emplace_front
#define mp make_pair
#define fst first
#define snd second
#define sqr(x) ((x) * (x))
#define ls(x) x << 1
#define rs(x) x << 1 | 1
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
// typedef __int128 bll;
// typedef unsigned __int128 ubll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int MAXN = 2.5e3 + 10, LOGN = log2(MAXN) + 1, inf = ~0U >> 2, INF = ~0U >> 1;
const int dx[] = {0, 0, 1, -1}, dy[] = {1, -1, 0, 0};
namespace stupid_lrc {
	template <typename T> il bool read(T &x) {
		x = 0; bool f = false; char ch;
 		while (!isdigit(ch = getchar())) {
			f ^= !(ch ^ '-');
			if (ch == EOF) return false;
		}
		while (isdigit(ch)) x = (x << 1) + (x << 3) + (ch & 15), ch = getchar();
		if (f) x = ~x + 1; return true;
	}
	il int read() {int x; read(x); return x;}

	template <typename T> il bool read(pair <T, T> &x) {return read(x.fst) && read(x.snd);}

	template <typename T> il void gmin(T &x, T y) {x = x < y ? x : y;}

 	template <typename T> il void gmax(T &x, T y) {x = x > y ? x : y;}

	template <typename T, typename ...L>
	il bool read(T &x, L &...y) {return read(x) && read(y...);}

	template <typename T> il T lowbit(const T &x) {return x & -x;}
}
using namespace stupid_lrc;
vector <int> g[2510];
int vis[2510], d[2510], id[2510][2510];

il void dfs(int x) {
//	cout << "!!" << x << ' ' << d[x] << endl;
	if (g[x].size() < d[x]) {
		cout << "> " << g[x].size() + 1 << endl;
		int y; read(y); read(d[y]); id[x][y] = g[x].size() + 1;
		return g[x].eb(y), dfs(y); 
	} vis[x] = 1;
//		puts("Sbsb");
	rep1(i, 0, d[x] - 1) if (!vis[g[x][i]]) {
		cout << "> " << i + 1 << endl;
		int y; read(y); read(d[y]); dfs(y);
		cout << "> " << id[y][x] << endl;
		read(); read(); assert(vis[g[x][i]]);
	}
} 

int main() {
	for (int T = read(); T--; ) {
		rep1(i, 1, 2.5e3) vis[i] = 0, g[i].clear();
		int x; read(x); read(d[x]); dfs(x);
		cout << "! ";
		rep1(u, 1, 2.5e3) for (auto v : g[u]) if (u < v) cout << u << ' ' << v << ' '; cout << endl;
		scanf("%*s");
	} 
	return 0;
}