#include <iostream>
#include <algorithm>
#include <vector>
#include <utility>
#include <set>
using std::cin, std::cout;

#define F(i, a, b) for(int i = a; i <= (b); ++i)
#define F2(i, a, b) for(int i = a; i < (b); ++i)
#define dF(i, a, b) for(int i = a; i >= (b); --i)

void Solve();
int main() {
//    cin.sync_with_stdio(false);
//    cin.tie(nullptr);
    int tests = 1;
    cin >> tests;
    while (tests--)
        Solve();
    return 0;
}

using LL = long long;
const int Mod = 998244353;

const int Inf = 0x3f3f3f3f;
const LL InfLL = 0x3f3f3f3f3f3f3f3f;

const int MN = 500005;

int n;
int del[MN];
std::vector<int> G[MN];

int root;
std::vector<int> V;
int siz[MN], mxs[MN];
void DFS(int u, int p) {
    V.push_back(u);
    siz[u] = 1;
    mxs[u] = 0;
    for (int v : G[u]) if (v != p && !del[v])
        DFS(v, u), mxs[u] = std::max(mxs[u], siz[v]), siz[u] += siz[v];
}
void Del(int u, int p) {
    del[u] = 1;
    for (int v : G[u]) if (v != p && !del[v])
        Del(v, u);
}

void Solve() {
    cin >> n;
    F(i, 1, n) G[i].clear(), del[i] = 0;
    F(i, 1, n) {
        int x, y;
        cin >> x >> y;
        if (x) G[i].push_back(x), G[x].push_back(i);
        if (y) G[i].push_back(y), G[y].push_back(i);
    }
    root = 1;
    while (true) {
        V.clear();
        DFS(root, 0);
        int tot = (int)V.size();
        root = 0;
        for (int u : V) {
            mxs[u] = std::max(mxs[u], tot - siz[u]);
            if (!root || mxs[root] > mxs[u])
                root = u;
        }
        //V.clear();
       // DFS(root, 0);
//        std::cerr << "\t\troot = " << root << '\n';
        if (tot == 1) {
            cout << "! " << root << '\n';
            cout << std::flush;
            return ;
        }
        std::vector<std::pair<int, int>> w;
        for (int v : G[root]) if (!del[v])
            w.push_back({siz[v], v});
        std::sort(w.begin(), w.end());
        std::reverse(w.begin(), w.end());
        int deg = (int)w.size();
        if (deg == 1) {
//            std::cerr << "\t\tdeg = 1" << '\n';
            cout << "? " << root << ' ' << w[0].second << '\n';
            cout << std::flush;
            int t;
            cin >> t;
            if (t == 0) del[w[0].second] = 1;
            else del[root] = 1, root = w[0].second;
        } else if (deg == 2) {
//            std::cerr << "\t\tdeg = 2" << '\n';
            cout << "? " << w[0].second << ' ' << w[1].second << '\n';
            cout << std::flush;
            int t;
            cin >> t;
            if (t == 0) Del(root, w[0].second), root = w[0].second;
            else if (t == 1) Del(w[0].second, root), Del(w[1].second, root);
            else Del(root, w[1].second), root = w[1].second;
        } else {
//            std::cerr << "\t\tdeg = 3" << '\n';
            cout << "? " << w[0].second << ' ' << w[1].second << '\n';
            cout << std::flush;
            int t;
            cin >> t;
            if (t == 0) Del(root, w[0].second), root = w[0].second;
            else if (t == 1) Del(w[0].second, root), Del(w[1].second, root);
            else Del(root, w[1].second), root = w[1].second;
        }
    }
}