#include <bits/stdc++.h>
using namespace std;
const int N = 2e5 + 7;
vector<int> p[N];
int siz[N];
int root = 0;
int ma = 1e9;
int query(int u, int v)
{
    cout << "? " << u << ' ' << v << endl;
    int x;
    cin >> x;
    return x;
}
void answer(int x)
{
    cout << "! " << x << endl;
    return;
}
void dfs1(int u, int fa)
{
    siz[u] = 1;
    for (int v : p[u])
    {
        if (v == fa)
            continue;
        dfs1(v, u);
        siz[u] += siz[v];
    }
}
void dfs2(int u, int fa, int pre_s)
{
    int tmp = pre_s;
    int sum = pre_s;
    for (int v : p[u])
    {
        if (v == fa)
            continue;
        sum += siz[v];
        tmp = max(tmp, siz[v]);
    }
    if (tmp < ma)
    {
        ma = tmp;
        root = u;
    }
    for (int v : p[u])
    {
        if (v == fa)
            continue;
        dfs2(v, u, sum - siz[v]+1);
    }
}
void solve()
{
    int n, m, k;
    cin >> n;
    for (int i = 1; i <= n; i++)
        p[i].clear();
    vector<int> du(n + 1, 0);
    for (int i = 1; i <= n; i++)
    {
        int u, v;
        cin >> u >> v;
        du[u]++, du[v]++;
        if (u)
            p[i].push_back(u), p[u].push_back(i);
        if (v)
            p[i].push_back(v), p[v].push_back(i);
    }
    for (int i = 1; i <= n; i++)
        if (!du[i])
            root = i;
    ma = n;
    dfs1(root, 0);
    dfs2(root, 0, 0);
    int f1 = -1;
    while (p[root].size() >= 1)
    {
        auto tmp = p[root];
        if (tmp.size() < 2)
            tmp.push_back(root);
        f1 = query(tmp[0], tmp[1]);
        if (f1 == 0)
        {
            p[tmp[0]].erase(find(p[tmp[0]].begin(), p[tmp[0]].end(), root));
            root = tmp[0];
        }
        else if (f1 == 1)
        {
            p[root].clear();
            if (tmp.size() >= 3 && tmp[2] != root)
                p[root].push_back(tmp[2]);
        }
        else
        {
            if (tmp[1] != root)
            {
                p[tmp[1]].erase(find(p[tmp[1]].begin(), p[tmp[1]].end(), root));
                root = tmp[1];
            }
            else
            {
                break;
            }
        }
        ma = n;
        dfs1(root, 0);
        dfs2(root, 0, 0);
        // cerr << "root:" << ' ' << root << '\n';
    }
    answer(root);
}

int main()
{
    // #ifdef LOCAL
    //     freopen("data.in", "r", stdin);
    //     freopen("data.out", "w", stdout);
    // #endif
    // ios::sync_with_stdio(false);
    // cin.tie(nullptr);
    int T;
    cin >> T;
    while (T--)
        solve();
    return 0;
}