#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n;
  cin >> n;
  vector<vector<int>> tree(n + 1);
  for (int i = 1; i < n; i++) {
    int x, y;
    cin >> x >> y;
    tree[x].push_back(y);
    tree[y].push_back(x);
  }
  vector<bool> alive(n + 1, true);
  while (true) {
    vector<int> degree(n + 1);
    vector<int> leaf;
    for (int i = 1; i <= n; i++) {
      if (!alive[i]) continue;
      for (int j : tree[i])
        if (alive[j]) {
          degree[i]++;
        }
      if (degree[i] == 1) leaf.push_back(i);
    }
    if (leaf.size() < 2) {
      vector<int> x;
      for (int i = 1; i <= n; i++)
        if (alive[i]) {
          x.push_back(i);
        }
      assert(x.size() == 1);
      cout << "! " << x[0] << endl;
      return 0;
    }
    cout << "? " << leaf[0] << " " << leaf[1] << endl;
    int lca;
    cin >> lca;
    if ((lca == leaf[0]) || (lca == leaf[1])) {
      cout << "! " << lca << endl;
      return 0;
    }
    alive[leaf[0]] = alive[leaf[1]] = false;
  }
  return 0;
}
