#include "bits/stdc++.h"
#define int long long
#define ull unsigned long long
#define PII pair<int, int>
#define TIII tuple<int, int, int>
#define LL __int128
#define eps 1e-6
using namespace std;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
constexpr int N = 2e6 + 10, M = 2e6 + 10, mod = 1e9 + 7, inf = 1e18;
int n, m;

void solve()
{
    cin >> n;
    vector<vector<int>> adj(n + 1, vector<int>());
    for(int i = 1; i <= n; i ++)
    {
        int L, R;
        cin >> L >> R;
        if(L) adj[i].emplace_back(L), adj[L].emplace_back(i);
        if(R) adj[i].emplace_back(R), adj[R].emplace_back(i);
    }
    
    vector<int> point;
    vector<int> vis(n + 1), maxsize(n + 1), size(n + 1);
    function<void(int,int)> dfs=[&](int u,int fa)
    {
        point.emplace_back(u);
        maxsize[u] = 0, size[u] = 1;
        for(auto& v:adj[u])
        {
            if(v == fa || vis[u]) continue;
            dfs(v, u);
            size[u] += size[v];
            maxsize[u] = max(maxsize[u], size[v]);
        }
    };
    function<void(int,int)> tag=[&](int u,int fa)
    {
        vis[u] = true;
        for(auto& v:adj[u])
        {
            if(v == fa || vis[u]) continue;
            tag(v, u);
        }
    };
    auto ask=[&](int a, int b)
    {
        cout <<"? " << a << " " << b << endl;
        int ans;
        cin >> ans;
        return ans;
    };
    int root = 1;
    while(1)
    {
        vector<int>().swap(point);
        dfs(root, 0);
        int tot = point.size();
        root = 0;
        for(auto& u : point)
        {
            maxsize[u] = max(maxsize[u], tot - size[u]);
            if(!root || maxsize[u] < maxsize[root]) root = u;
        }
        if(tot == 1)
        {
            cout << "! " << root << endl;
            return;
        }
        vector<int> vec;
        for(auto& v:adj[root])
        {
            if(!vis[v]) vec.emplace_back(v);
        }
        sort(vec.begin(), vec.end(),[&](int i,int j)
        {
            return size[i] > size[j];
        });
        if(vec.size() == 1)
        {
            if(ask(root, vec[0]) == 0)
            {
                vis[vec[0]] = true;
            }
            else vis[root]= true, root = vec[0];
        }
        else
        {
            int ans = ask(vec[0], vec[1]);
            if(ans == 0)
            {
                tag(root, vec[0]), root = vec[0];
            }
            else if(ans == 1)
            {
                tag(vec[0], root), tag(vec[1], root);
            }
            else tag(root, vec[1]), root = vec[1];
        }
    }
}


signed main()
{
    std::ios::sync_with_stdio(false);
    cin.tie(nullptr), cout.tie(nullptr);
    cout << fixed << setprecision(2);

#ifndef ONLINE_JUDGE
    freopen("in.txt", "rt", stdin);
    freopen("out.txt", "wt", stdout);
#endif

    int Cases = 1;
    cin >> Cases;
    while (Cases--)
    {
        solve();
    }
    return 0;
}