// https://qoj.ac/contest/1522/problem/8056
// Travel 2
#include<bits/stdc++.h>

using i64 = long long;
const int N = 3000;

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    std::cout << std::fixed << std::setprecision(10);
    
    int t;
    std::cin >> t;
    while (t--) {
        int x, d;
        std::cin >> x >> d;
        x--;
        
        std::vector<std::vector<int>> adj(1);
        std::vector<int> fa(1, -1), cur(1);
        int tot = 1;
        auto go = [&](int x, int i) {
            int y, d;
            std::cout << "> " << i + 1 << std::endl;
            std::cin >> y >> d;
            y--;
            if (tot < y + 1) {
                tot = std::max(tot, y + 1);
                adj.resize(tot);
                fa.resize(tot);
                cur.resize(tot);
            }
            if (adj[y].empty()) {
                // new node 
                adj[y].assign(d, -1);    
                fa[y] = x;
            } 
            return y;
        };    
        auto find = [&](int x, int y) {
            return std::find(adj[x].begin(), adj[x].end(), y) - adj[x].begin();   
        };

        adj[0].resize(d);
        while (x != -1) {
            if (cur[x] == adj[x].size()) {
                if (x == 0) break;
                go(x, find(x, fa[x]));
                x = fa[x];
                continue;
            }
            int y = go(x, cur[x]++);
            adj[x][cur[x] - 1] = y;
            if (y == fa[x]) {
                assert(go(y, find(y, x)) == x);
                continue;
            }  
            x = y;
        }
        std::vector<std::pair<int, int>> ans;
        for (int i = 0; i < tot; i++) {
            for (int j = 0; j < adj[i].size(); j++) {
                if (i < adj[i][j]) {
                    ans.emplace_back(i, adj[i][j]);  
                }
            }
        }
        std::cout << "! ";
        for (auto [x, y] : ans) {
            std::cout << x + 1 << " " << y + 1 << " ";
        }
        std::cout << std::endl;
        std::string tt;
        std::cin >> tt;
    }
    return 0;
}