#include<bits/stdc++.h>

using namespace std;
using vi = vector<int>;
#define all(x) (x).begin(), (x).end()
#define pb push_back
#define Sz(x) ((int)(x).size())

typedef long long ll;
typedef unsigned long long ull;

int n;
int query(int x, int y)
{
    cout << "? " << x << " " << y << endl;
    int res;
    cin >> res;
    return res;
}

void ans(int x)
{
    cout << "! " << x << endl;
}

const int N = 1e5 + 2;
vi e[N];
int sz[N], del[N], maxs[N];

void divn(int u, int s)
{
    if (s == 1)
    {
        ans(u);
        return;
    }
    int ms = s + 1, root = -1;
    function<void(int, int)> center = [&](int u ,int fa) {
        sz[u] = 1;
        maxs[u] = 0;
        for (auto v : e[u]) {
            if (del[v] || v == fa) continue;
            center(v, u);
            maxs[u] = max(maxs[u], sz[v]);
            sz[u] += sz[v];
        }
        maxs[u] = max(maxs[u], s - sz[u]);
        if (maxs[u] < ms) ms = maxs[u], root = u;
    };
    center(u, -1);

    cerr << root << "\n";
    vector<array<int, 2>> son;
    for (auto v : e[root]) {
        if (del[v]) continue;
        function<void(int, int)> dfs = [&](int u, int fa) {
            sz[u] = 1;
            for (auto v : e[u]) {
                if (del[v] || v == fa) continue;
                dfs(v, u);
                sz[u] += sz[v];
            }
        };
        dfs(v, root);
        son.pb({sz[v], v});
    }

    sort(all(son), greater<>());
    int m = Sz(son);
    assert(m);
    if (m == 1)
    {
        auto [cnt, v] = son[0];
        assert(cnt == 1);
        int res = query(root, v);
        assert(res != 1);
        if (res == 0) ans(root);
        else ans(v);
    }
    else
    {
        auto [c1, v1] = son[0];
        auto [c2, v2] = son[1];
        int res = query(v1, v2);
        if (res == 1)
        {
            del[v1] = del[v2] = 1;
            divn(root, s - sz[v1] - sz[v2]);
        }
        else
        {
            del[root] = 1;
            if (res == 0)
                divn(v1, sz[v1]);
            else
                divn(v2, sz[v2]);
        }
    }

}

void sol()
{
    cin >> n;
    for (int i = 1; i <= n; i++)
    {
        e[i].clear();
        del[i] = sz[i] = maxs[i] = 0;
    }
    for (int i = 1; i <= n; i++)
    {
        int x, y;
        cin >> x >> y;
        if (x) 
        {
            e[i].pb(x);
            e[x].pb(i);
        }
        if (y) 
        {
            e[i].pb(y);
            e[y].pb(i);
        }
    }
    divn(1, n);
}

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int T;
    cin >> T;
    while (T --) sol();
    return 0;
}

/*
 1
 5
 0 0
 1 5
 2 4
 0 0
 0 0
*/