#include <bits/stdc++.h>

#define ll long long

void solve(){
    int n;
    std::cin >> n;

    std::vector<std::vector<int>> adj(n);

    for (int i = 0; i < n; i++){
        int L, R;
        std::cin >> L >> R;
        L--, R--;
        if (R >= 0) {
            adj[i].push_back(R);
            adj[R].push_back(i);
        }
        if (L >= 0) {
            adj[i].push_back(L);
            adj[L].push_back(i);
        }
    }

    std::vector<int> cut(n);

    auto work = [&](int root){
        std::vector<int> size(n, 1e9), max(n, 1e9);
        int tot = 0;
        auto dfs = [&](auto &&self, int x, int fa)->void{
            size[x] = 1;
            max[x] = 0;
            tot++;
            for (auto y : adj[x]){
                if (y == fa || cut[y]) continue;
                self(self, y, x);
                size[x] += size[y];
                max[x] = std::max(max[x], size[y]);
            }
        };
        dfs(dfs, root, -1);
        int heavy = root, val = std::max(max[heavy], tot - size[heavy]);
        for (int i = 0; i < n; i++){
            if (val > std::max(max[i], tot - size[i])){
                heavy = i;
                val = std::max(max[i], tot - size[i]);
            }
        }
        std::vector<std::pair<int, int>> son;
        for (auto y : adj[heavy]){
            if (cut[y]) continue;
            son.push_back({size[y], y});
        }
        std::sort(son.begin(), son.end(), std::greater<>());
        return std::make_pair(heavy, son);
    };

    auto query = [](int u, int v){
        std::cout << "? " << u + 1 << ' ' << v + 1 << std::endl;
        int t;
        std::cin >> t;
        return t;
    };

    int root = 0;
    while (true){
        auto [x, son] = work(root);
        int dag = 0;
        dag = son.size();
        std::cout << dag << " ";
        std::cout << x + 1 << std::endl;
        if (dag == 0) {
            std::cout << "! ";
            std::cout << x + 1 << std::endl;
            return;
        }else if (dag == 1){
            int t = query(x, son[0].second);
            if (t == 0){
                std::cout << "! ";
                std::cout << x + 1 << std::endl;
            }else{
                std::cout << "! ";
                std::cout << son[0].second + 1 << std::endl;
            }
            return;
        }else if (dag == 2){
            int t = query(son[0].second, son[1].second);
            if (t == 0){
                cut[x] = 1;
                root = son[0].second;
            }else if (t == 1){
                std::cout << "! ";
                std::cout << x + 1 << std::endl;
                return;
            }else{
                cut[x] = 1;
                root = son[1].second;
            }

        }else if (dag == 3){
            int t = query(son[0].second, son[1].second);
            if (t == 0){
                cut[x] = 1;
                root = son[0].second;
            }else if (t == 1){
                cut[son[0].second] = 1;
                cut[son[1].second] = 1;
                root = son[2].second;
            }else{
                cut[x] = 1;
                root = son[1].second;
            }
        }
    }

}

int main() {

    int t;

    std::cin >> t;

    while (t--){
        solve();
    }

    return 0;
}