#include <bits/stdc++.h>
using namespace std;
const int maxn = 2e5 + 5;
long long m, t, n, ar[maxn], br[maxn];
void ask(int x, int y) { cout << "? " << x << " " << y << endl; }
int main() {
  std::ios::sync_with_stdio(false);
  cin.tie(0);
  cin >> n;
  vector<vector<int>> v(n + 1);
  for (int a, b, i = 1; i < n; i++) {
    cin >> a >> b;
    ar[a]++;
    ar[b]++;
    v[a].push_back(b);
    v[b].push_back(a);
  }
  queue<int> q;
  for (int i = 1; i <= n; i++) {
    if (ar[i] == 1) q.push(i);
  }
  t = n;
  while (t >= 2) {
    int x, y;
    x = q.front();
    q.pop();
    y = q.front();
    q.pop();
    ask(x, y);
    int r;
    cin >> r;
    if (r == y || r == x) {
      cout << "! " << r << endl;
      return 0;
    }
    br[x] = 1;
    br[y] = 1;
    t -= 2;
    for (int i : v[x]) {
      if (!br[i]) {
        ar[i]--;
        if (ar[i] == 1) q.push(i);
      }
    }
    for (int i : v[y]) {
      if (!br[i]) {
        ar[i]--;
        if (ar[i] == 1) q.push(i);
      }
    }
  }
  for (int i = 1; i <= n; i++) {
    if (!br[i]) {
      cout << "! " << i << endl;
      return 0;
    }
  }
  return 0;
}
