#include <bits/stdc++.h>
using namespace std;
using i64 = long long;
const i64 mod = 998244353;
vector<vector<int>> con;
vector<int> ctr; // 重心
const int maxn = 2e5 + 9;
int n, m, allsz;
int sz[maxn], mss[maxn], fa[maxn];
void dfs(int u, int f)
{
    fa[u] = f;
    sz[u] = 1, mss[u] = 0;
    for (auto v : con[u])
    {
        if (v == f)
            continue;
        dfs(v, u);
        sz[u] += sz[v];
        mss[u] = max(mss[u], sz[v]);
    }
    mss[u] = max(mss[u], allsz - sz[u]);
    if (mss[u] <= allsz / 2)
    {
        ctr.push_back(u);
    }
} // 搜重心
void solve()
{
    cin >> n;
    con.assign(n + 1, vector<int>());
    ctr.clear();
    int rt = 1;
    for (int i = 1; i <= n; i++)
    {
        int l, r;
        cin >> l >> r;
        if (l)
        {
            con[i].push_back(l);
            con[l].push_back(i);
        }
        if (r)
        {
            con[i].push_back(r);
            con[r].push_back(i);
        }
    }
    for (int i = 1; i <= n; i++)
    {
        sort(con[i].begin(), con[i].end());
        con[i].erase(unique(con[i].begin(), con[i].end()), con[i].end());
    }
    function<int(int, int)> ask = [&](int l, int r) -> int
    {
        cout << "? " << l << " " << r << endl;
        cout.flush();
        int x;
        cin >> x;
        return x;
    };
    allsz = n;
    dfs(rt, 0);
    rt = ctr[0];
    ctr.clear();
    dfs(rt, 0);
    while (sz[rt] > 1)
    {
        if (con[rt].size() == 1)
        {
            int l = rt, r = con[rt][0];
            int seg = ask(l, r);
            if (seg == 0)
            {
                cout << "! " << rt << endl;
                return;
            }
            else
            {
                cout << "! " << r << endl;
                return;
            }
        }
        if (con[rt].size() == 2)
        {
            int l = con[rt][0], r = con[rt][1];
            int seg = ask(l, r);
            if (seg == 0)
            {
                auto it = find(con[l].begin(), con[l].end(), rt);
                if (it != con[l].end())
                    con[l].erase(it);
                allsz = sz[l];
                ctr.clear();
                dfs(l, 0);
                rt = ctr[0];
                ctr.clear();
                dfs(rt, 0);
            }
            else if (seg == 2)
            {
                auto it = find(con[r].begin(), con[r].end(), rt);
                if (it != con[r].end())
                    con[r].erase(it);
                allsz = sz[r];
                ctr.clear();
                dfs(r, 0);
                rt = ctr[0];
                ctr.clear();
                dfs(rt, 0);
            }
            else
            {
                cout << "! " << rt << endl;
                return;
            }
        }
        else if (con[rt].size() > 2)
        {
            sort(con[rt].rbegin(), con[rt].rend(), [&](int x, int y) -> bool
                 { return sz[x] < sz[y]; });
            int l = con[rt][0], r = con[rt][1];
            int seg = ask(l, r);
            if (seg == 0)
            {
                auto it = find(con[l].begin(), con[l].end(), rt);
                if (it != con[l].end())
                    con[l].erase(it);
                allsz = sz[l];
                ctr.clear();
                dfs(l, 0);
                rt = ctr[0];
                ctr.clear();
                dfs(rt, 0);
            }
            else if (seg == 2)
            {
                auto it = find(con[r].begin(), con[r].end(), rt);
                if (it != con[r].end())
                    con[r].erase(it);
                allsz = sz[r];
                ctr.clear();
                dfs(r, 0);
                rt = ctr[0];
                ctr.clear();
                dfs(rt, 0);
            }
            else
            {
                auto it = find(con[rt].begin(), con[rt].end(), l);
                if (it != con[rt].end())
                    con[rt].erase(it);
                it = find(con[rt].begin(), con[rt].end(), r);
                if (it != con[rt].end())
                    con[rt].erase(it);
                allsz = sz[rt] - sz[l] - sz[r];
                ctr.clear();
                dfs(rt, 0);
                rt = ctr[0];
                ctr.clear();
                dfs(rt, 0);
            }
        }
    }
    cout << "! " << rt << endl;
}

signed main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int t = 1;
    cin >> t;
    while (t--)
        solve();
}