#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e3 + 5;
const int inf = 0x3f3f3f3f;
const long long mod = 1e9 + 7;
const double eps = 1e-6;
vector<int> g[maxn];
vector<int> tree[maxn];
int deep[maxn], son[maxn];
int cnt, mx;
void dfs(int x, int y) {
  int sz = g[x].size();
  deep[x] = 0;
  son[x] = -1;
  for (int i = 0; i < sz; ++i) {
    int to = g[x][i];
    if (to == y) {
      continue;
    }
    tree[x].push_back(to);
    dfs(to, x);
    if (son[x] == -1 || deep[son[x]] < deep[to]) {
      son[x] = son[to];
    }
  }
  if (son[x] == -1) {
    son[x] = x;
  } else {
    deep[x] = deep[son[x]] + 1;
  }
}
struct node {
  int id, w;
  bool operator<(const node& rhs) const { return w > rhs.w; }
} nd[maxn];
int solve(int x) {
  int sz = tree[x].size();
  for (int i = 0; i < sz; ++i) {
    nd[i] = {tree[x][i], deep[tree[x][i]]};
  }
  sort(nd, nd + sz);
  int hf = sz / 2;
  for (int i = 0; i < hf; ++i) {
    int a = nd[i * 2].id, b = nd[i * 2 + 1].id;
    ++cnt;
    printf("? %d %d\n", son[a], son[b]);
    fflush(stdout);
    int c;
    scanf("%d", &c);
    if (c != x) {
      return solve(c);
    }
    if (cnt >= mx) break;
  }
  if ((sz & 1) == 1 && cnt < mx) {
    ++cnt;
    printf("? %d %d\n", x, son[nd[sz - 1].id]);
    fflush(stdout);
    int c;
    scanf("%d", &c);
    if (c != x) {
      return solve(c);
    }
  }
  return x;
}
int main() {
  int n;
  scanf("%d", &n);
  cnt = 0, mx = n / 2;
  for (int i = 1; i < n; ++i) {
    int u, v;
    scanf("%d%d", &u, &v);
    g[u].push_back(v);
    g[v].push_back(u);
  }
  dfs(1, -1);
  printf("! %d\n", solve(1));
  fflush(stdout);
  return 0;
}
