#include <bits/stdc++.h>
using namespace std;
using i64 = long long;
using pii = pair<int, int>;
constexpr int maxn = 2500 + 10;
map<int, int> e[maxn];
map<int, int> g[maxn];
void dfs(int u, int fa, int deg)
{
    for (int i=1;i<=deg;++i)
    {
        if (g[u].find(i) != g[u].end()) continue;
        cout << "> " << i << endl;
        int v, dv;
        cin >> v >> dv;
        g[u][i] = v;
        e[u][v] = i;
        if (e[v].find(u) != e[v].end())
        {
            cout << "> " << e[v][u] << endl;
            cin >> v >> dv;
        }
        else dfs(v, u, dv);
    }
    if (fa)
    {
        cout << "> " << e[u][fa] << endl;
        int v, dv;
        cin >> v >> dv;
    }
}
void solve()
{
    for (int i=0;i<maxn;++i) g[i].clear(), e[i].clear();
    int x, d;
    cin >> x >> d;
    dfs(x, 0, d);
    vector<pii> ans;
    for (int i=0;i<maxn;++i)
        for (auto [j, p] : e[i])
            if (i < j) ans.emplace_back(pii(i, j));
    cout << "!";
    for (auto [x, y] : ans) cout << ' ' << x << ' ' << y;
    cout << endl;
    string s;
    cin >> s;
}
int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    int t;
    cin >> t;
    while (t--) solve();
    return 0;
}