#include<bits/stdc++.h>
using namespace std;
#define int long long
const int N = 1e5+5;
vector<int>g[N];
bool del[N];
int mxs[N], sz[N];

void solve(int u, int siz){
    int root = -1, ms = siz + 1;
    if(siz == 1){
    	cout << "! " << u << endl;
    	return ;
    }
    function<void(int, int)> dfs1 = [&](int u, int fa){
        sz[u] = 1; mxs[u] = 0;
        for(auto v: g[u])if(v!=fa && !del[v]){
            dfs1(v, u);
            sz[u] += sz[v];
            mxs[u] = max(mxs[u], sz[v]);
        }
        mxs[u] = max(mxs[u], siz - sz[u]);
        if(mxs[u] < ms) ms = mxs[u], root = u;
    };
    dfs1(u, -1);
    function<void(int, int)> dfs2 = [&](int u, int fa){
        sz[u] = 1;
        for(auto v: g[u])if(v!=fa && !del[v]){
            dfs2(v, u);
            sz[u] += sz[v];
        }
    };
    dfs2(root, -1);
    int du = 0;
    vector<int>vec;
	for(auto v: g[root])if(!del[v]){
    	du++;
    	vec.push_back(v);
    }
	if(du == 3){
        sort(vec.begin(), vec.end(), [&](int l, int r){
            return sz[l] > sz[r];
        });
        int x = vec[0], y = vec[1];
        cout << "? " << x << ' ' << y << endl;
        int fk; cin >> fk;
        if(fk == 1){
            del[x] = del[y] = 1;
            solve(vec[2], sz[vec[2]] + 1);
        }else if(fk == 0){
            del[root] = 1;
            solve(x, sz[x]);
        }else {
            del[root] = 1;
            solve(y, sz[y]);
        }
        return ;
    }else if(du == 2){
        int x = vec[0], y = vec[1];
        cout << "? " << x << ' ' << y << endl;
        int fk; cin >> fk;
        if(fk == 1){
            cout << "! " << root << endl;
            return ;
        }else if(fk == 0){
            del[root] = 1;
            solve(x, sz[x]);
        }else {
            del[root] = 1;
            solve(y, sz[y]);
        }
    }else {
        int x = vec[0];
        cout << "? " << root << ' ' << x << endl;
        int fk; cin >> fk;
        if(fk == 0){
            cout << "! " << root << endl;
            return ;
        }else {
            cout << "! " << x << endl;
            return ;
        }
    }
}

void solve(){
    int n; cin >> n;
    for(int i=1; i<=n; i++) g[i].clear(), del[i] = 0;
    for(int i=1; i<=n; i++){
        int u, v; cin >> u >> v;
        if(u){
            g[i].push_back(u);
            g[u].push_back(i);
        }
        if(v){
            g[i].push_back(v);
            g[v].push_back(i);
        }
    }
    solve(1, n);
}

signed main (){
    int t;
    cin>>t;
    while(t--) solve();
}