#include <bits/stdc++.h>
using namespace std;
#define IOS ios::sync_with_stdio(0), cin.tie(0), cout.tie(0)
using PII = pair<int, int>;
#define endl "\n"
const int N = 2e5 + 5;
vector<int> G[N];
int siz[N], f[N], vis[N], cnt[N];
int lst = 0;
int mid = 0;
void dfs(int u, int fa)
{
    f[u] = fa;
    siz[u] = 1;
    int flag = 1;
    for (auto v : G[u])
    {
        if (v == fa || vis[v])
            continue;
        dfs(v, u);
        if (siz[v] > lst / 2)
            flag = 0;
        siz[u] += siz[v];
    }
    if (vis[u])
        return;
    if (lst - siz[u] > lst / 2)
        flag = 0;
    if (flag)
        mid = u;
}
void solve()
{
    int n;
    cin >> n;
    for (int i = 1; i <= n; i++)
    {
        G[i].clear();
        vis[i] = 0;
        f[i] = 0;
        siz[i] = 0;
    }
    for (int i = 1; i <= n; i++)
    {
        int u, v;
        cin >> u >> v;
        if (v)
        {
            G[i].push_back(v);
            G[v].push_back(i);
        }
        if (u)
        {
            G[i].push_back(u);
            G[u].push_back(i);
        }
    }
    lst = n;
    int rt = 1;
    mid = 0;
    while (1)
    {
        int x;
        mid = rt;
        dfs(rt, 0);
       // cerr << "mid " << mid << endl;
        vector<pair<int, int>> ve;
        for (auto v : G[mid])
        {
            if (vis[v])
                continue;
            if (v == f[mid])
                ve.emplace_back(lst - siz[mid], v);
            else
                ve.emplace_back(siz[v], v);
        }
        sort(ve.begin(), ve.end(), greater<pair<int, int>>());
        if (ve.size() == 3)
        {
            cout << "? " << ve[0].second << " " << ve[1].second << endl;
            cout.flush();
            cin >> x;
            if (x == 0)
            {
            	vis[mid]=1;
                lst = siz[ve[0].second];
                rt = ve[0].second;
            }
            else if (x == 1)
            {
                vis[ve[0].second] = 1;
                vis[ve[1].second] = 1;
                lst = siz[ve[2].second] + 1;
                rt=mid;
            }
            else
            {
            	vis[mid]=1;
               lst = siz[ve[1].second];
                rt = ve[1].second;
            }
        }
        else if (ve.size() == 2)
        {
            cout << "? " << ve[0].second << " " << ve[1].second << endl;
            cout.flush();
            cin >> x;
            if (x == 0)
            {
                vis[mid] = 1;
                lst = siz[ve[0].second];
                rt = ve[0].second;
            }
            else if (x == 1)
            {
                cout << "! " << mid << endl;
                return;
            }
            else
            {
                vis[mid] = 1;
                lst = siz[ve[1].second];
                rt = ve[1].second;
            }
        }
        else if (ve.size() == 1)
        {
            cout << "? " << mid << " " << ve[0].second << endl;
            cout.flush();
            cin >> x;
            if (x == 0)
            {
                cout << "! " << mid << endl;
                cout.flush();
            }
            else
            {
                cout << "! " << ve[0].second << endl;
                cout.flush();
            }
            return;
        }
        else
        {
            cout << "! " << rt << endl;
            cout.flush();
            return;
        }
    }
}
signed main()
{
    IOS;
    int t = 1;
    cin >> t;
    while (t--)
    {
        solve();
    }
    return 0;
}