#include <bits/stdc++.h>

using i64 = long long;

struct Node {
    int id, sz;
};

void solve() {
    int n;
    std::cin >> n;
    std::vector<std::vector<Node>> adj(n + 1);
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= 2; j++) {
            int x;
            std::cin >> x;
            if (x != 0) {
                adj[i].push_back({x, 0});
                adj[x].push_back({i, 0});
            }
        }
    }

    auto query = [&](int a, int b) -> int {
        std::cout << "? " << a << " " << b << std::endl;
        int res;
        std::cin >> res;
        return res;
    };

    int siz = n, root = 1;
    int a, b, target;

    auto dfs = [&](auto self, int u, int fa) -> int {
        int res = 1;
        for (auto &t: adj[u]) {
            int v = t.id;
            if (v != fa) {
                t.sz = self(self, v, u);
                res += t.sz;
            }
        }
        std::vector<int> vec;
        for (auto &t: adj[u]) {
            int v = t.id;
            vec.push_back(t.sz);
            if (v == fa) {
                t.sz = siz - res;
            }
        }

        if (vec.size() == 3) {
            int mx = *std::max_element(vec.begin(), vec.end());
            if (mx <= siz - mx) {
                target = u;
                if (adj[u][0].sz == mx) {
                    a = adj[u][0].id;
                    b = adj[u][1].id;
                } else {
                    a = adj[u][1].id;
                    b = adj[u][2].id;
                }
            }
        } else if (vec.size() == 2) {
            if (abs(vec[0] - vec[1]) <= 1) {
                target = u;
                a = vec[0];
                b = vec[1];
            }
        }
        return res;
    };

    while (siz >= 3) {
        dfs(dfs, root, -1);
        int t = query(a, b);
        if (t == 0) {
            for (auto it: adj[target]) {
                if (it.id == a) {
                    siz = it.sz;
                }
            }
            for (auto it = adj[a].begin(); it != adj[a].end();) {
                if (it->id == target) {
                    adj[a].erase(it);
                    break;
                } else {
                    it++;
                }
            }
            root = a;
        } else if (t == 1) {
            for (auto it: adj[target]) {
                if (it.id == a || it.id == b) {
                    siz -= it.sz;
                }
            }
            for (auto it = adj[target].begin(); it != adj[target].end();) {
                if (it->id == a || it->id == b) {
                    adj[target].erase(it);
                } else {
                    it++;
                }
            }
            root = target;
        } else {
            std::swap(a, b);
            for (auto it: adj[target]) {
                if (it.id == a) {
                    siz = it.sz;
                }
            }
            for (auto it = adj[a].begin(); it != adj[a].end();) {
                if (it->id == target) {
                    adj[a].erase(it);
                    break;
                } else {
                    it++;
                }
            }
            root = a;
        }
    }
    if (siz == 2) {
        dfs(dfs, root, -1);
        a = target, b = adj[target][0].id;
        int t = query(a, b);
        if (t == 0) {
            std::cout << "! " << a << std::endl;
        } else {
            std::cout << "! " << b << std::endl;
        }
    } else {
        std::cout << "! " << target << std::endl;
    }
}

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr), std::cout.tie(nullptr);

    int T;
    std::cin >> T;

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

    return 0;
}

answer.code: In function ‘void solve()’:
answer.code:34:20: error: use of ‘auto’ in lambda parameter declaration only available with ‘-std=c++14’ or ‘-std=gnu++14’
   34 |     auto dfs = [&](auto self, int u, int fa) -> int {
      |                    ^~~~
answer.code: In lambda function:
answer.code:39:28: error: ‘self’ cannot be used as a function
   39 |                 t.sz = self(self, v, u);
      |                        ~~~~^~~~~~~~~~~~
answer.code: In function ‘void solve()’:
answer.code:75:12: error: no match for call to ‘(solve()::<lambda(int, int, int)>) (solve()::<lambda(int, int, int)>&, int&, int)’
   75 |         dfs(dfs, root, -1);
      |         ~~~^~~~~~~~~~~~~~~
answer.code:34:16: note: candidate: ‘solve()::<lambda(int, int, int)>’
   34 |     auto dfs = [&](auto self, int u, int fa) -> int {
      |                ^
answer.code:34:16: note:   no known conversion for argument 1 from ‘solve()::<lambda(int, int, int)>’ to ‘int’
answer.code:125:12: error: no match for call to ‘(solve()::<lambda(int, int, int)>) (solve()::<lambda(int, int, int)>&, int&, int)’
  125 |         dfs(dfs, root, -1);
      |         ~~~^~~~~~~~~~~~~~~
answer.code:34:16: note: candidate: ‘solve()::<lambda(int, int, int)>’
   34 |     auto dfs = [&](auto self, int u, int fa) -> int {
      |                ^
answer.code:34:16: note:   no known conversion for argument 1 from ‘solve()::<lambda(int, int, int)>’ to ‘int’