#include <bits/stdc++.h>
using namespace std;
const int N = 1e3 + 10, mod = 1e9 + 7;
set<int> g[N], l;
bool handle(int v, int p, int v1, int v2) {
  if (v == v1 || v == v2) {
    return true;
  }
  bool val = false;
  for (int u : g[v])
    if (u != p) val |= handle(u, v, v1, v2);
  return val;
}
void clearr(int v, int p) {
  for (int u : g[v])
    if (u != p) clearr(u, v);
  g[v].clear();
  l.erase(v);
}
int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int n;
  cin >> n;
  for (int i = 0; i < n - 1; i++) {
    int u, v;
    cin >> u >> v;
    u--;
    v--;
    g[u].insert(v);
    g[v].insert(u);
  }
  for (int i = 0; i < n; i++)
    if (g[i].size() == 1) l.insert(i);
  while (l.size() > 1) {
    auto it = l.begin();
    int u = *it;
    it++;
    int v = *it;
    cout << "? " << u + 1 << " " << v + 1 << " " << endl;
    int x;
    cin >> x;
    x--;
    if (x == u || x == v) {
      cout << "! " << x + 1 << endl;
      return 0;
    }
    vector<int> vv;
    for (int uu : g[x])
      if (handle(uu, x, u, v)) vv.push_back(uu);
    for (int y : vv) {
      g[x].erase(y);
      clearr(y, x);
    }
    l.clear();
    for (int i = 0; i < n; i++)
      if (g[i].size() == 1) l.insert(i);
    if (l.size() == 0) {
      cout << "! " << x + 1 << endl;
      return 0;
    }
  }
  cout << "! " << *l.begin() + 1 << endl;
  return 0;
}
