#include <bits/stdc++.h>

using std::map;
using std::vector;
using std::pair;
typedef pair<int, int> pir;

const int N = 5e4 + 5;
int fa[N], deg[N], now_rk[N];
int n, top, T_data;
map<int, int> ma[N];
map<int, bool> tag[N];
vector<pir> ans;
bool vis[N];
char s[N];

void append(int x, int y)
{
	if (x > y)
		std::swap(x, y);
	if (!tag[x][y])
	{
		ans.emplace_back(std::make_pair(x, y));	
		tag[x][y] = true;
	}
}

void dfs(int x)
{
	int y, dy;
	if (now_rk[x] < deg[x])
	{
		++now_rk[x];
		printf("> %d\n", now_rk[x]);
		fflush(stdout);
		scanf("%d%d", &y, &dy);
		ma[x][y] = now_rk[x];
		append(x, y);
		if (y == fa[x])
		{
			if (now_rk[x] == deg[x])
				dfs(y);
			else 
			{
				printf("> %d\n", ma[fa[x]][x]);
				fflush(stdout);
				scanf("%d%d", &y, &dy);
				dfs(x);		
			}
		}
		else 
		{
			if (!vis[y])
			{
				if (y > n)
					n = y;
				deg[y] = dy;
				vis[y] = true;
				fa[y] = x;
			}
			dfs(y); 
		}
	}
	else if (fa[x])
	{
		printf("> %d\n", ma[x][fa[x]]);
		fflush(stdout);
		scanf("%d%d", &y, &dy);
		dfs(fa[x]);	
	}	
}

int main()
{
	scanf("%d", &T_data);
	while (T_data--)
	{
		int src, dsrc;
		scanf("%d%d", &src, &dsrc);
		n = src;
		vis[src] = true;
		deg[src] = dsrc;
		dfs(src);
		
		printf("!");
		for (pir e : ans)
			printf(" %d %d", e.first, e.second);
		putchar('\n');
		fflush(stdout);
		scanf("%s", s + 1);
		
		ans.clear();
		for (int i = 1; i <= n; ++i)
		{
			vis[i] = false;
			deg[i] = now_rk[i] = fa[i] = 0;
			ma[i].clear();
			tag[i].clear();
		}
	}
}