#include<bits/stdc++.h>
#define int long long
#define pii pair<int, int>
#define ll long long
#define pb push_back
using namespace std;
int lim;
int query(int a,int c,int b){
    cout << "? "<<a << " " << b << endl;
    int res;
    cin>>res;
    lim--;
    if(res==0)return a;
    if(res==1)return c;
    if(res==2)return b;
}
const int N = 2e5 + 5;
int dep[N];
int par[N][22];
int C = 19;
int lca(int x,int y){
    if(dep[y]>dep[x])swap(x,y);
    for (int i = C - 1;i>=0;i--){
        if(dep[par[x][i]]>=dep[y])
            x = par[x][i];
    }
    if(x==y)return y;
    for (int i = C - 1;i>=0;i--){
        if(par[x][i]!=par[y][i]){
            x=par[x][i];
            y=par[y][i];
        }
    }
    return par[x][0];
}
int dis(int u,int v){
    return dep[u] + dep[v] - 2 * dep[lca(u, v)];
}
int n;
struct que{
    int a,c,b;
    int mxsz;
    bool operator<(const que&B)const {
        return mxsz < B.mxsz;
    }
    void print(){
        cout << a << " " << c << " " << b << " " << mxsz << endl;
    }
};

void work(vector<vector<int>>&a,set<int>node){
    if(node.size()==1){
        cout << "! "<<*node.begin() << endl;
        return;
    }
    if(node.size()==2){
        int ans = query(*node.begin(), *node.begin(), *node.rbegin());
        cout << "! " << ans << endl;
        return;
    }
    int cnt = node.size();
    vector<int>sz(n+1);
    int root = *node.begin();
    for(auto p:node)if(dep[p]<dep[root])
        root = p;
    function<void(int, int)> dfs = [&](int u, int f) {
        sz[u]++;
        for(auto p:a[u]){
            if(p==f)continue;
            if(!node.count(p))continue;
            dfs(p,u);
            sz[u] += sz[p];
        }
    };
    auto fsz = [&](int u, int f) {
        if(dep[f]<dep[u])return sz[u];
        return cnt  - sz[f];
    };
    dfs(root, 0);
    vector<que> Query;
    for(auto p:node){
        for (int i = 0; i < (int)a[p].size();i++)
            for (int j = i + 1; j < (int)a[p].size();j++){
            int mxsz=0;
            int sz1 = fsz(a[p][i], p);
            int sz2 = fsz(a[p][j], p);
            mxsz = max({sz1, sz2, cnt - sz1 - sz2});
            que now = {a[p][i], p, a[p][j], mxsz};
            Query.pb(now);
            // now.print();
        }
    }
    sort(Query.begin(),Query.end());
    // cout << Query[0].mxsz << endl;
    // cout << Query[0].a<<" "<<Query[0].c<<" "<<Query[0].b << endl;
    assert(Query[0].mxsz<= cnt/2);
    set<int> s;
    s.insert(Query[0].a);
    s.insert(Query[0].b);
    s.insert(Query[0].c);
    int newtr = query(Query[0].a,Query[0].c,Query[0].b);
    s.erase(newtr);
    int other1 = *s.begin();
    int other2 = *s.rbegin();
    set<int> newnode;
    for(auto p:node){
        if(dis(p,newtr)<dis(p,other1)&&dis(p,newtr)<dis(p,other2))
            newnode.insert(p);
    }
    work(a, newnode);
}

void solve() {
    cin >> n;
    lim = __lg(n);
    vector<vector<int>> a(n + 1);
    set<int> node;
    set<int> last;
    for(int i=1;i<=n;i++)
        last.insert(i);
    for(int i=1;i<=n;i++){
        int u,v;
        cin>>u>>v;
        last.erase(u);
        last.erase(v);
        if(u)a[i].pb(u),a[u].pb(i);
        if(v)a[i].pb(v),a[v].pb(i);
        node.insert(i);
    }
    int root = *last.begin();
    function<void(int, int)> dfs = [&](int u, int f) {
        dep[u]=dep[f]+1;
        par[u][0] = f;
        for (int i = 1; i < C;i++)
            par[u][i] = par[par[u][i - 1]][i - 1];
        for(auto p:a[u]){
            if(p==f)continue;
            dfs(p, u);
        }
    };
    dfs(root, 0);
    work(a,node);
}
signed main() {
    ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    int t = 1;
     cin >> t;
    while (t--)
        solve();
    return 0;
}