#include <bits/stdc++.h>
using namespace std;
#define all(x) (x).begin(), (x).end()
#define SZ(x) ((int)(x).size())
#define pb push_back
using ll = long long;
const ll mod = 1000000007;
const ll INF = 1ll << 60;
const int inf = 1 << 30;
const int N = 200010;

/*
找到重心 rt 作为根
若 rt 的度数为 0，代表当前点就是答案
若 rt 的度数为 1，代表当前只有 2 个点，直接询问即可
若 rt 的度数为 2，询问 rt 的 2 个邻居后根据情况分类讨论即可
若 rt 的度数为 3，询问 rt 的最大的两个邻居
*/
int n, sz[N], maxs[N], c;
bool del[N], ok;
vector<int> adj[N];
inline int ask(int u, int v) {
    c += 1;
    cout << "? " << u << " " << v << endl;
    int x; cin >> x; return x;
}
inline void qry(int u) {
    if (!ok) {
        cout << "! " << u << endl;
        ok = true;
    }
}
inline void solve(int u, int s) {
    int ms = s + 1, rt = -1;
    auto dfs1 = [&](auto dfs1, int u, int par) -> void {
        sz[u] = 1, maxs[u] = 0;
        for (auto v : adj[u]) {
            if (del[v] || v == par) continue;
            dfs1(dfs1, v, u);
            sz[u] += sz[v];
            maxs[u] = max(maxs[u], sz[v]);
        }
        maxs[u] = max(maxs[u], s - sz[u]);
        if (maxs[u] < ms) {
            ms = maxs[u], rt = u;
        }
    };
    dfs1(dfs1, u, -1);

    // cerr << "root = " << rt << endl;

    vector<int> node;
    for (auto v : adj[rt]) {
        if (!del[v]) {
            node.push_back(v);            
        }
    }

    if (node.size() == 0) {
        qry(rt);
    } else if (node.size() == 1) {
        int op = ask(rt, node[0]);
        if (op == 0) {
            qry(rt);
        } else {
            qry(node[0]);
        }
    } else if (node.size() == 2) {
        int op = ask(node[0], node[1]);
        del[rt] = true;
        if (op == 0) {
            solve(node[0], sz[node[0]]);
        } else if (op == 1) {
            qry(rt);
        } else {
            solve(node[1], sz[node[1]]);
        }
    } else {
        sort(all(node), [&](auto a, auto b) {
            return sz[a] > sz[b];
        });
        int op = ask(node[0], node[1]);
        if (op == 0) {
            del[rt] = true;
            solve(node[0], sz[node[0]]);
        } else if (op == 1) {
            del[node[0]] = true;
            del[node[1]] = true;
            solve(rt, sz[node[2]] + 1);
        } else {
            del[rt] = true;
            solve(node[1], sz[node[1]]);
        }
    }

}
void solve() {
    cin >> n;
    for (int i = 1; i <= n; ++i) {
        adj[i].clear();
        del[i] = false;
    }
    for (int i = 1; i <= n; ++i) {
        int ls, rs; cin >> ls >> rs;
        if (ls) {
            adj[ls].pb(i);
            adj[i].pb(ls);
        }
        if (rs) {
            adj[rs].pb(i);
            adj[i].pb(rs);
        }
    }
    c = 0;
    ok = false;
    solve(1, n);
    assert(c <= __lg(n));
}
/*
1
5
0 0
1 5
2 4
0 0
0 0

1
8
2 0
8 6
0 0
3 0
0 0
7 0
0 0
5 4
*/
signed main(void) {
    ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
    int Test = 1;
    cin >> Test;
    while (Test--) solve();
    return 0;
}