#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef double db;
// #define max(a, b) ((a) > (b) ? (a) : (b))
// #define min(a, b) ((a) < (b) ? (a) : (b))
#define pb push_back
#define LNF 1e18
#define INF 0x7fffffff
#define int long long
#define lowbit(x) ((x) & (-x))
#define abs(x) llabs(x)
// #define endl '\n'
#define Y() cout << "Yes" << endl
#define N() cout << "No" << endl
const db eps = 1e-9;
const int mod = 998244353;
const int MAXN = 2e5 + 5;
vector<pair<int, int>> pth[500005];
int siz[500005], maxp[500005], vis[500005], root, ans = 0, n, t;

void get_root(int pos, int fa, int total)
{
    siz[pos] = 1;
    maxp[pos] = 0;
    for (auto &[to, w] : pth[pos])
    {
        if (to == fa || vis[to])
            continue;
        get_root(to, pos, total);
        siz[pos] += siz[to];
        maxp[pos] = max(maxp[pos], siz[to]);
    }
    maxp[pos] = max(maxp[pos], total - siz[pos]);
    if (!root || maxp[pos] < maxp[root])
        root = pos;
}

int calc(int pos)
{
    int good = 0;
    vector<int> nu;
    for (auto &[to, w] : pth[pos])
    {
        if (!vis[to])
        {
            good++;
            nu.push_back(to);
        }
    }
    //cout << pos << " " << good << endl;
    if (good == 0)
    {
        cout << "! " << pos << endl;
        return -1;
    }
    else if (good == 1)
    {
        cout << "? " << nu[0] << " " << pos << endl;

        cin >> t;
        if (t == 0)
            cout << "! " << nu[0] << endl;
        else
            cout << "! " << pos << endl;
        return -1;
    }
    else if (good == 2)
    {
        cout << "? " << nu[0] << " " << nu[1] << endl;

        cin >> t;
        if (t == 1)
        {
            cout << "! " << pos << endl;
            return -1;
        }
        else if (t == 0)
        {
            return nu[0];
        }
        else
            return nu[1];
    }
    else
    {
        cout << "? " << nu[0] << " " << nu[1] << endl;

        cin >> t;
        if (t == 1)
        {
            return nu[2];
        }
        else if (t == 0)
        {
            return nu[0];
        }
        else
            return nu[1];
    }
}
void sol(int pos)
{

    int nu = calc(pos);
    if (nu == -1)
        return;
    if (t == 1)
    {
        for (auto &[to, w] : pth[pos])
        {
            if (to != nu)
                vis[to] = 1;
        }
        maxp[root = 0] = n;
        get_root(pos, 0, siz[nu] + 1);
        sol(root);
    }
    else
    {

        vis[pos] = 1;
        maxp[root = 0] = n;
        get_root(nu, 0, siz[nu]);
        sol(root);
    }
}

void add(int a, int b)
{
    pth[a].push_back({b, 1});
    pth[b].push_back({a, 1});
}
void solve()
{
    cin >> n;
    for (int i = 1; i <= n; i++)
    {
        int a, b;
        cin >> a >> b;
        if (a)
            add(a, i);
        if (b)
            add(b, i);
    }
    maxp[root = 0] = n;
    get_root(1, 0, n);
    sol(root);
    for (int i = 1; i <= n; i++)
        pth[i].clear();
}
signed main()
{
    std::ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int T = 1;
    cin >> T;
    while (T--)
        solve();
    return 0;
}