#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
template <class T>
using vc = vector<T>;
template <class T>
using vvc = vc<vc<T>>;
template <class T>
using vvvc = vc<vvc<T>>;
#define overload5(a, b, c, d, e, name, ...) name
#define overload4(a, b, c, d, name, ...) name
#define overload3(a, b, c, name, ...) name
#define rep1(n) for (ll i = 0; i < n; ++i)
#define rep2(i, n) for (ll i = 0; i < n; ++i)
#define rep3(i, a, b) for (ll i = a; i < b; ++i)
#define rep4(i, a, b, c) for (ll i = a; i < b; i += c)
#define rep(...) overload4(__VA_ARGS__, rep4, rep3, rep2, rep1)(__VA_ARGS__)
#define rrep1(n) for (ll i = n; i--;)
#define rrep2(i, n) for (ll i = n; i--;)
#define rrep3(i, a, b) for (ll i = b; i-- > (a);)
#define rrep(...) overload4(__VA_ARGS__, rrep4, rrep3, rrep2, rrep1)(__VA_ARGS__)
#define each1(i, a) for (auto &&i : a)
#define each2(x, y, a) for (auto &&[x, y] : a)
#define each3(x, y, z, a) for (auto &&[x, y, z] : a)
#define each4(w, x, y, z, a) for (auto &&[w, x, y, z] : a)
#define each(...) overload5(__VA_ARGS__, each4, each3, each2, each1)(__VA_ARGS__)
#define all1(i) begin(i), end(i)
#define all2(i, a) begin(i), begin(i) + a
#define all3(i, a, b) begin(i) + a, begin(i) + b
#define all(...) overload3(__VA_ARGS__, all3, all2, all1)(__VA_ARGS__)
#define rall1(i) rbegin(i), rend(i)
#define rall2(i, a) rbegin(i), rbegin(i) + a
#define rall3(i, a, b) rbegin(i) + a, rbegin(i) + b
#define rall(...) overload3(__VA_ARGS__, rall3, rall2, rall1)(__VA_ARGS__)
template <class T>
bool chmin(T &a, const T &b) {
    if (a <= b) return 0;
    a = b;
    return 1;
}
template <class T>
bool chmax(T &a, const T &b) {
    if (a >= b) return 0;
    a = b;
    return 1;
}
template <class T, class U>
bool chmin(T &a, const U &b) {
    return chmin(a, (T)b);
}
template <class T, class U>
bool chmax(T &a, const U &b) {
    return chmax(a, (T)b);
}
void solve();
int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(20);
    ll t = 1;
    cin >> t;
    for (int i = 1; i <= t; i++) solve();
    return 0;
}
ll dy[] = {0, 0, 1, 0, -1}, dx[] = {0, 1, 0, -1, 0};
// ll dy[8] = {1, 1, 0, -1, -1, -1, 0, 1}, dx[8] = {0, 1, 1, 1, 0, -1, -1, -1};
void solve() {
    ll n;
    cin >> n;
    vvc<ll> g(n);
    rep(i, n) {
        ll l, r;
        cin >> l >> r;
        l--, r--;
        if (l >= 0) g[i].push_back(l), g[l].push_back(i);
        if (r >= 0) g[i].push_back(r), g[r].push_back(i);
    }
    ll r = 0;
    while (true) {
        vc<ll> dp(n);
        auto dfs = [&](auto &&dfs, ll from, ll par) -> void {
            dp[from] = 1;
            each(to, g[from]) {
                if (to == par) continue;
                dfs(dfs, to, from);
                dp[from] += dp[to];
            }
        };
        dfs(dfs, r, -1);
        ll rem = dp[r];
        if (rem == 1) break;
        dp.assign(n, 0);
        auto dfs2 = [&](auto &&dfs, ll from, ll par) -> void {
            dp[from] = 1;
            each(to, g[from]) {
                if (to == par) continue;
                dfs(dfs, to, from);
                dp[from] += dp[to];
            }
        };
        dfs2(dfs2, r, -1);
        vc<ll> vis(n);
        ll gra = r;
        vis[gra] = 1;
        while (true) {
            bool ok = true;
            for (auto to : g[gra]) {
                if (vis[to]) continue;
                if (dp[to] * 2 > rem) {
                    gra = to;
                    ok = false;
                    vis[gra] = 1;
                    break;
                }
            }
            if (ok) break;
        }
        if (g[gra].size() == 1) {
            ll u = g[gra][0], v = gra;
            cout << "? " << v + 1 << " " << u + 1 << endl;
            ll x;
            cin >> x;
            if (x == 0)
                cout << "! " << v + 1 << endl;
            else
                cout << "! " << u + 1 << endl;
            return;
        }
        vc<pair<ll, ll>> ord;
        for (auto to : g[gra]) {
            if (dp[to] < dp[gra])
                ord.push_back({dp[to], to});
            else
                ord.push_back({rem - dp[gra], to});
        }
        sort(ord.rbegin(), ord.rend());
        ll u = ord[0].second, v = ord[1].second;
        cout << "? " << v + 1 << " " << u + 1 << endl;
        ll x;
        cin >> x;
        if (x == 0) {
            r = v;
            vc<ll> era;
            for (auto to : g[v]) {
                if (to == gra) era.push_back(to);
                if (to == u) era.push_back(to);
            }
            sort(all(era));
            era.erase(unique(all(era)), era.end());
            for (auto e : era) g[v].erase(find(all(g[v]), e));
        } else if (x == 1) {
            r = gra;
            vc<ll> era;
            for (auto to : g[gra]) {
                if (to == u) era.push_back(to);
                if (to == v) era.push_back(to);
            }
            sort(all(era));
            era.erase(unique(all(era)), era.end());
            for (auto e : era) g[gra].erase(find(all(g[gra]), e));
        } else {
            r = u;
            vc<ll> era;
            for (auto to : g[u]) {
                if (to == gra) era.push_back(to);
                if (to == v) era.push_back(to);
            }
            sort(all(era));
            era.erase(unique(all(era)), era.end());
            for (auto e : era) g[u].erase(find(all(g[u]), e));
        }
    }
    cout << "! " << r + 1 << endl;
}