#include <bits/stdc++.h>
using namespace std;
unordered_set<int> g[1003], le, un;
int main() {
  int n;
  cin >> n;
  int i, j, x, y, cn = n;
  for (i = 1; i <= n - 1; ++i) cin >> x >> y, g[x].insert(y), g[y].insert(x);
  for (i = 1; i <= n; ++i)
    if (g[i].size() == 1) le.insert(i), un.insert(i);
  while (cn > 1) {
    auto it = le.begin();
    auto it2 = it;
    ++it2;
    cout << "? " << *it << ' ' << *it2 << "\n";
    cin >> x;
    if (x == *it or x == *it2) return cout << "! " << x << "\n", 0;
    for (auto it3 : g[*it]) g[it3].erase(*it);
    for (auto it3 : g[*it2]) g[it3].erase(*it2);
    g[*it].clear();
    g[*it2].clear();
    for (i = 1; i <= n; ++i)
      if (g[i].size() <= 1 and !un.count(i)) le.insert(i), un.insert(i);
    cn -= 2;
    le.erase(*it);
    le.erase(*it2);
  }
  cout << "! " << *le.begin() << "\n";
  return 0;
}
