#include <bits/stdc++.h>
#define all(x) begin(x), end(x)
#define sz(x) ((int)(x).size())
#ifdef memset0
#define log(...) fprintf(stderr, __VA_ARGS__)
#else
#define endl '\n'
#define log(...) (void(0))
#endif
using namespace std;
using ll = long long;
using lf = long double;
using ull = unsigned long long;

const int N = 1e5 + 9;
int T, n, fa[N], dep[N], bo;
vector<int> g[N];

void dfs(int u) {
  for (int v : g[u])
    if (v != fa[u]) {
      fa[v] = u;
      dep[v] = dep[u] + 1;
      dfs(v);
    }
}

int get_dis(int u, int v) {
  int dis = 0;
  while (u != v) {
    if (dep[u] > dep[v]) swap(u, v);
    ++dis, v = fa[v];
  }
  return dis;
}

int _s = -1;
int ask(int u, int v) {
#ifdef memset0
  int s1 = get_dis(u, _s);
  int s2 = get_dis(v, _s);
  if (s1 < s2) return 0;
  if (s1 > s2) return 2;
  return 1;
#else
  cout << "? " << u << " " << v << endl;
  cout << flush;
  int x;
  cin >> x;
  return x;
#endif
}

bool vis[N];
vector<int> nod;

void markall(int u, int f) {
  vis[u] = true;
  for (int v : g[u])
    if (v != f && !vis[v]) {
      markall(v, u);
    }
}

tuple<int, int> cho;
int mxp[N];
int search(int u, int f) {
  int s = 1;
  mxp[u] = 0;
  for (int v : g[u])
    if (v != f && !vis[v]) {
      int ch = search(v, u);
      s += ch;
      mxp[u] = max(mxp[u], ch);
    }
  mxp[u] = max(mxp[u], sz(nod) - s);
  cho = min(cho, make_tuple(mxp[u], u));
  return s;
}

int count_size(int u, int f) {
  int sum = 1;
  for (int v : g[u])
    if (!vis[v] && v != f) {
      sum += count_size(v, u);
    }
  return sum;
}

int solve() {
  log("!!! (internal) s = %d\n", _s);
  fill(vis + 1, vis + n + 1, false);
  int res = -1;
  int cnt = 0;
  while (true) {
    nod.clear();
    for (int i = 1; i <= n; i++)
      if (!vis[i]) {
        nod.emplace_back(i);
      }
    log("loop >> sz=%d\n", sz(nod));
    if (sz(nod) == 1) {
      res = nod[0];
      break;
    }
    ++cnt;
    if (sz(nod) == 2) {
      int u = nod[0], v = nod[1];
      int w = ask(u, v);
      res = w == 0 ? u : v;
      break;
    }
    int rt = nod[0];
    for (int u : nod)
      if (dep[u] < dep[rt]) {
        rt = u;
      }
    auto &[diff, u] = cho;
    diff = INT_MAX;
    search(rt, -1);
    log("searched: %d %d\n", diff, u);
    assert(diff != INT_MAX);
    vector<pair<int, int>> c;
    for (int t : g[u])
      if (!vis[t]) {
        c.emplace_back(count_size(t, u), t);
      }
    assert(2 <= sz(c) && sz(c) <= 3);
    sort(all(c));
    auto solve_uv = [&](int u, int v) {
      log("ask u=%d v=%d\n", u, v);
      int cho = ask(u, v);
      assert(cho != 1);
      if (cho == 0) {
        markall(v, u);
      } else {
        markall(u, v);
      }
    };
    auto solve_uw = [&](int u, int v, int w) {
      log("ask u=%d w=%d (v=%d)\n", u, w, v);
      int cho = ask(u, w);
      if (cho == 0) {
        markall(v, u);
      } else if (cho == 1) {
        markall(u, v);
        markall(w, v);
      } else if (cho == 2) {
        markall(v, w);
      }
    };
    if (sz(c) == 2) {
      if (c[0].first == c[1].first) {
        solve_uw(c[0].second, u, c[1].second);
      } else {
        solve_uv(u, c[1].second /* bigger subtree */);
      }
    } else {
      solve_uw(c[1].second, u, c[2].second);
    }
  }
  assert(res != -1);
  assert((1ull << cnt) <= n);
  return res;
}

void solve_main() {
  for (int u = 1; u <= n; u++)
    for (int v : g[u]) {
      log("edge %d %d\n", u, v);
    }
  fill(fa + 1, fa + n + 1, 0);
  fill(dep + 1, dep + n + 1, 0);
  dep[1] = 1;
  dfs(1);
#ifdef memset0
  for (_s = 1; _s <= n; _s++) {
    int ans = solve();
    cout << "! " << ans << endl;
    assert(ans == _s);
  }
#else
  int ans = solve();
  cout << "! " << ans << endl;
  cout << flush;
#endif
}

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int rand(int l, int r) { return uniform_int_distribution<>(l, r)(rng); }

int uni[N];
int uni_find(int x) {
  if (x == uni[x]) return x;
  return uni[x] = uni_find(uni[x]);
}

int main() {
#ifdef memset0
  freopen("G.in", "r", stdin);
#endif
  cin.tie(0)->sync_with_stdio(0);
  // int T = 100000, N = 5;
  // for (int t = 1; t <= T; t++) {
  //   n = rand(2, N);
  //   for (int i = 1; i <= n; i++) {
  //     g[i].clear();
  //     uni[i] = i;
  //   }
  //   for (int u, v, i = 1; i < n; i++) {
  //     do {
  //       u = rand(1, n);
  //       v = rand(1, n);
  //     } while (u == v || find(all(g[u]), v) != g[u].end() || sz(g[u]) == 2 || sz(g[v]) == 2 || uni_find(u) == uni_find(v));
  //     g[u].emplace_back(v);
  //     g[v].emplace_back(u);
  //     uni[uni_find(u)] = uni_find(v);
  //     log("edge[%d] = %d, %d\n", i, u, v);
  //   }
  //   solve_main();
  // }
  // return 0;

  cin >> T;
  while (T--) {
    cin >> n;
    for (int i = 1; i <= n; i++) {
      g[i].clear();
    }
    for (int u, v, i = 1; i <= n; i++) {
      cin >> u >> v;
      if (u) {
        g[i].emplace_back(u);
        g[u].emplace_back(i);
      }
      if (v) {
        g[i].emplace_back(v);
        g[v].emplace_back(i);
      }
    }
    solve_main();
  }
}