#include <bits/stdc++.h>

int query(int a, int b) {
    std::cout << "? " << a << " " << b << std::endl;
    int x;
    std::cin >> x;
    return x;
}

void answer(int node) {
    std::cout << "! " << node << std::endl;
}

struct Graph {
    std::vector<std::vector<int>> graph;
    std::vector<int> subtree;
    std::vector<bool> blocked;

    Graph(int n): graph(1 + n), subtree(1 + n), blocked(1 + n) {}

    void predfs(int node, int father = 0) {
        //std::cerr << node << "\n";
        subtree[node] = 1;
        for (auto it: graph[node]) {
            if (it != father && !blocked[it]) {
                predfs(it, node);
                subtree[node] += subtree[it];
            }
        }
    }

    std::vector<int> get_subtrees(int node) {
        std::vector<int> choices;
        for (auto it: graph[node])
            if (!blocked[it])
                choices.push_back(it);
        return choices;
    }

    int get_centroid(int root, int node, int father = 0) {
        for (auto it: graph[node])
            if (it != father && !blocked[it] && subtree[it] > subtree[root] / 2)
                return get_centroid(root, it, node);
        return node;
    }

    void solve(int root) {
        //std::cerr << "Call from root: " << root << "\n";
        predfs(root);
        int c = get_centroid(root, root);
        predfs(c);


        std::vector<int> choices = get_subtrees(c);

        if (choices.size() == 0) {
            answer(root);
            return;
        }

        // single edge
        if (choices.size() == 1) {
            int x = query(c, choices[0]);
            if (x == 0)
                answer(c);
            else
                answer(choices[0]);
            return;
        }

        if (choices.size() == 2) {
            int x = query(choices[0], choices[1]);
            
            if (x == 1) {
                answer(c);
                return;
            }

            blocked[c] = true;
            if (x == 0)
                solve(choices[0]);
            else
                solve(choices[2]);
        }

        if (choices.size() == 3) {
            std::sort(choices.begin(), choices.end(), [&](int a, int b) {
                return subtree[a] > subtree[b];
            });

            int x = query(choices[0], choices[1]);

            if (x == 0) {
                blocked[c] = true;
                solve(choices[0]);
                return;
            } else if (x == 2) {
                blocked[c] = true;
                solve(choices[1]);
                return;
            } else {
                blocked[choices[0]] = blocked[choices[1]] = true;
                solve(c);
                return;
            }
        }
    }
};

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

    Graph G(n);

    for (int i = 1; i <= n; i++) {
        for (int j = 0; j < 2; j++) {
            int x;
            std::cin >> x;
            if (x != 0) {            
                G.graph[x].push_back(i);
                G.graph[i].push_back(x);
            }
        }
    }

    G.solve(1);
}

int main() {
    int t;

    std::cin >> t;
    while (t--) solve_test();

    return 0;
}