#include <bits/stdc++.h>
using namespace std;
template <typename Arg1>
void __f(const char* name, Arg1&& arg1) {
  cout << name << " : " << arg1 << "\n";
}
template <typename Arg1, typename... Args>
void __f(const char* names, Arg1&& arg1, Args&&... args) {
  const char* comma = strchr(names + 1, ',');
  cout.write(names, comma - names) << " : " << arg1 << " , ";
  __f(comma + 1, args...);
}
const int N = 1e3 + 10;
vector<vector<int>> g;
vector<int> par, height;
int n;
int bfs(int root) {
  int last = root;
  par[root] = -1;
  height[root] = 0;
  queue<int> q;
  q.push(root);
  while (!q.empty()) {
    int u = q.front();
    q.pop();
    last = u;
    for (auto v : g[u])
      if (v != par[u]) {
        par[v] = u;
        height[v] = height[u] + 1;
        q.push(v);
      }
  }
  return last;
}
void dfs(int u, int par, int tar) {
  for (int v : g[u])
    if (v != par) {
      if (v == tar) {
        g[u].erase(find(g[u].begin(), g[u].end(), v));
        g[v].erase(find(g[v].begin(), g[v].end(), u));
      } else
        dfs(v, u, tar);
    }
}
int main() {
  int i, j, k, n, m;
  cin >> n;
  g.resize(n);
  par.resize(n);
  height.resize(n);
  for (i = 0; i < n - 1; ++i) {
    int u, v;
    cin >> u >> v;
    u--, v--;
    g[u].push_back(v);
    g[v].push_back(u);
  }
  int x, y, q;
  x = bfs(0);
  y = bfs(x);
  cout << "? " << x + 1 << " " << y + 1 << endl;
  cin >> q;
  q--;
  while (1) {
    dfs(x, -1, q);
    dfs(y, -1, q);
    if (g[q].size() == 0) {
      cout << "! " << q + 1 << endl;
      return 0;
    };
    x = bfs(q);
    y = bfs(x);
    cout << "? " << x + 1 << " " << y + 1 << endl;
    cin >> q;
    q--;
  }
  return 0;
}
