#include <bits/stdc++.h>
using namespace std;
const int NN = 1e7 + 7;
const int N = 1e6 + 7;
const int M = 17;
const int mod = 1e9 + 7;
vector<int> t[N];
void solve1() {
  int n;
  cin >> n;
  vector<int> v(n + 1);
  for (int i = 1; i < n; i++) {
    int x, y;
    cin >> x >> y;
    t[x].push_back(y);
    t[y].push_back(x);
    v[x] += 1;
    v[y] += 1;
  }
  vector<int> g;
  for (int i = 1; i <= n; i++) {
    if (v[i] == 1) g.push_back(i);
  }
  for (int i = 0; i < (int)g.size() - 1; i += 2) {
    int x = g[i];
    int y = g[i + 1];
    cout << "? " << x << " " << y << endl;
    int w;
    cin >> w;
    if (w == x || w == y) {
      cout << "! " << w;
      return;
    }
    for (auto xx : t[x]) {
      v[xx] -= 1;
      if (v[xx] == 1) g.push_back(xx);
    }
    for (auto xx : t[y]) {
      v[xx] -= 1;
      if (v[xx] == 1) g.push_back(xx);
    }
  }
  cout << "! " << g.back();
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  srand(time(0));
  int cghf = 1;
  while (cghf--) {
    solve1();
  }
}
