#include <bits/stdc++.h>
const long long int MOD = 1e9 + 7;
using namespace std;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
std::vector<int> adj[1005];
unordered_set<int> nu, rem, lf;
void dfs(int u, int par) {
  bool leaf = true;
  for (int v : adj[u]) {
    if (v != par && nu.find(v) == nu.end()) {
      leaf = false;
      dfs(v, u);
    }
  }
  if (leaf) lf.insert(u);
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  int n;
  cin >> n;
  for (int i = 1; i < n; ++i) {
    int u, v;
    cin >> u >> v;
    adj[u].push_back(v);
    adj[v].push_back(u);
    rem.insert(u);
    rem.insert(v);
  }
  int ans = -1;
  while (rem.size() != 1) {
    lf.clear();
    int u = *rem.begin();
    dfs(u, u);
    if (lf.size() == 1) lf.insert(u);
    int a = *lf.begin();
    lf.erase(lf.begin());
    int b = *lf.begin();
    lf.erase(lf.begin());
    cout << "? " << a << " " << b << endl;
    cin.sync();
    int x;
    cin >> x;
    if (x == a || x == b) {
      ans = x;
      break;
    } else {
      nu.insert(a);
      nu.insert(b);
      rem.erase(rem.find(a));
      rem.erase(rem.find(b));
    }
  }
  if (ans != -1)
    cout << "! " << ans << endl;
  else
    cout << "! " << *rem.begin() << endl;
  return 0;
}
