#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using ull = unsigned long long;

#define rep(i,n) for(ll i=0;i<n;++i)
#define all(a) (a).begin(),(a).end()
ll intpow(ll a, ll b){ ll ans = 1; while(b){ if(b & 1) ans *= a; a *= a; b /= 2; } return ans; }
ll modpow(ll a, ll b, ll p){ ll ans = 1; while(b){ if(b & 1) (ans *= a) %= p; (a *= a) %= p; b /= 2; } return ans; }
template<class T> T div_floor(T a, T b) { return a / b - ((a ^ b) < 0 && a % b); }
template<class T> T div_ceil(T a, T b) { return a / b + ((a ^ b) > 0 && a % b); }
template <typename T, typename U> inline bool chmin(T &x, U y) { return (y < x) ? (x = y, true) : false; }
template <typename T, typename U> inline bool chmax(T &x, U y) { return (x < y) ? (x = y, true) : false; }


void solve() {
    ll N;
    cin>>N;
    vector<vector<ll>> edge(N);
    vector<pair<ll,ll>> el;
    rep(i,N-1){
        ll u,v;
        cin>>u>>v;
        u--;
        v--;
        edge[u].push_back(v);
        edge[v].push_back(u);
        el.push_back({u,v});
    }
    vector<ll> color(N,-1);
    color[0]=0;
    stack<ll> st;
    st.push(0);
    while (st.size()>0){
        ll cp=st.top();st.pop();
        for (ll np:edge[cp]){
            if (color[np]>=0)continue;
            color[np]=color[cp]^1;
            st.push(np);
        }
    }
    auto query=[](vector<ll> A){
        cout<<"? ";
        for (auto a:A){
            cout<<a+1<<' ';
        }
        cout<<endl;
        string S;
        cin>>S;
        assert (S!="Invalid");
        return (S=="Yes");
    };
    vector<ll> C;
    for (auto &[a,b]:el){
        if (color[a]==1){
            swap(a,b);
        }
        C.push_back(a);
    }
    if (query(C)){
        for (auto &[a,b]:el){
            swap(a,b);
        }
    }
    ll l=0;
    ll r=N-1;
    while (r-l>1){
        ll mid=(l+r)/2;
        vector<ll> C;
        rep(i,N-1){
            if (l<=i and i<mid){
                C.push_back(el[i].second);
            }
            else{
                C.push_back(el[i].first);
            }
        }
        if (query(C)){
            r=mid;
        }
        else{
            l=mid;
        }
    }
    cout<<"! "<<el[l].second+1<<endl;
    return;
}


int main() {
    ll T=1;
    while (T--){
        solve();
    }
    return 0;
}