#include<bits/stdc++.h>
using namespace std;
// #define endl '\n'
using ll = long long;
const int MAX = 3e5 + 5;

void solve(){
    int n; cin >> n;
    vector<set<int>> graph(n + 1);
    for (int i = 1; i <= n; i ++){
        int x, y; cin >> x >> y;
        if (x) graph[x].insert(i), graph[i].insert(x);
        if (y) graph[y].insert(i), graph[i].insert(y);
    }
    int t = n, cur = 1;
    vector<int> siz(n + 1);
    function<void(int, int)> dfs1 = [&](int u, int p){
        siz[u] = 1;
        for (int v : graph[u]){
            if (v == p) continue;
            dfs1(v, u);
            siz[u] += siz[v];
        }
    };
    int p = 0;
    function<void(int, int)> dfs2 = [&](int u, int pre){
        int maxx = t - siz[u];
        
        for (int v : graph[u]){
            if (v == pre) continue;
            maxx = max(maxx, siz[v]);
            dfs2(v, u);
        }
        // cerr << u << ' ' << maxx << ' ' << t << ' ' << endl;
        if (maxx <= t / 2) p = u;
    };
    dfs1(1, 0);
    while (t > 1){
        dfs2(cur, 0);
        // cout << p << ' ' << t << endl;
        if (graph[p].size() == 3){
            array<int, 3> a;
            auto it = graph[p].begin();
            for (int j = 0; j < 3; j ++){
                a[j] = *it;
                it ++;
            }
            cout << "? " << a[0] << ' ' << a[2] << endl;
            int x; cin >> x;
            graph[p].erase(a[0]);
            graph[p].erase(a[2]);
            graph[a[0]].erase(p);
            graph[a[2]].erase(p);
            cur = a[x];
        }
        else if (graph[p].size() == 2){
            array<int, 2> a;
            auto it = graph[p].begin();
            for (int j = 0; j < 2; j ++){
                a[j] = *it;
                it ++;
            }
            cout << "? " << a[0] << ' ' << a[1] << endl;
            int x; cin >> x;
            graph[p].erase(a[0]);
            graph[p].erase(a[1]);
            graph[a[0]].erase(p);
            graph[a[1]].erase(p);
            if (x == 0) cur = a[0];
            else if (x == 2) cur = a[1];
            else{
                cout << "! " << p << endl;
                return;
            }
        }
        else{
            auto i = *graph[p].begin();
            cout << "? " << i << ' ' << p << endl;
            int x; cin >> x;
            if (x == 0) cout << "! " << i << endl;
            else cout << "! " << p << endl;
            return;
        }
        dfs1(cur, 0);
        t = siz[cur];
    }
    cout << "! " << cur << endl;
}
signed main(){
    // ios::sync_with_stdio(0);cin.tie(0);
    // cout << fixed << setprecision(10);
    int T;cin>>T;while (T--)
        solve();
}