#include <bits/stdc++.h>
using namespace std;
const int MAXN = 212345;
int marc[MAXN], sub[MAXN];
vector <int> grafo[MAXN];
void dfs1(int v, int p) {
    //printf("%d\n", v);
    sub[v] = 1;
    for(int i = 0; i < grafo[v].size(); i++) {
        int viz = grafo[v][i];
        if(marc[viz] == 1 || viz == p) continue;
        dfs1(viz, v);
        sub[v] += sub[viz];
    }
}
int dfs(int v, int p, int a) {
    for(int i = 0; i < grafo[v].size(); i++) {
        int viz = grafo[v][i];
        if(marc[viz] == 1 || viz == p) continue;
        if(sub[viz] >= a) {
            return dfs(viz, v, a);
        }
    }
    return v;
}
int main() {
    int n;
    scanf("%d", &n);
    for(int i = 0; i < n - 1; i++) {
        int a, b;
        scanf("%d %d", &a, &b);
        grafo[a].push_back(b); grafo[b].push_back(a);
    }
    int at = 1;
    int cn;
    int cnt = 0;
    while(true) {
        if(cnt == 36) return 0;
        dfs1(at, at);
        //printf("%d\n", sub[at]);
        cn = dfs(at, at, (sub[at]) /2);
        marc[cn] = 1;
        printf("? 2 %d\n", cn);
        cnt++;
        fflush(stdout);
        scanf("%d", &at);
        if(at == 0) break;
    }
    printf("! %d\n", cn);
    fflush(stdout);
    return 0;
}