#include <bits/stdc++.h>
#define N 2000001
using namespace std;

int work(){
    int i, n; cin >> n;
    vector<int> lc(n + 1);
    vector<int> rc(n + 1);
    vector<int> fa(n + 1);
    vector<vector<int> > to(n + 1);
    for(i=1;i <= n;i++){
        cin >> lc[i] >> rc[i];
        fa[lc[i]] = i;
        fa[rc[i]] = i;
        if(lc[i]) {
            to[i].push_back(lc[i]);
            to[lc[i]].push_back(i);
        }
        if(rc[i]) {
            to[i].push_back(rc[i]);
            to[rc[i]].push_back(i);
        }
    }
    int rt = 0, Ans;
    vector<int> siz(n + 1);
    vector<int> mx(n + 1);
    vector<bool> vis(n + 1);
    auto root =[&](auto self, int u, int f, int total) -> void{
        siz[u] = 1; mx[u] = 0;
        for(auto v:to[u]){
            if(v == f || vis[v]) continue;
            self(self, v, u, total);
            siz[u] += siz[v];
            mx[u] = max(mx[u],siz[v]);
        }
        mx[u] = max(mx[u],total - siz[u]);
        //cout << u << "-" << mx[u] << endl;
        if(!rt || mx[u] < mx[rt]) rt = u;
    };
    auto dfs =[&] (auto self, int u) -> void{
        vis[u] = 1;
        //cout <<"dfs" << u <<endl;
        int num = 0;
        for(auto v:to[u]) if(!vis[v]) num++;
        if(num == 3){
            cout <<"? " << lc[u] << " " << rc[u] <<endl;
            int t, v; cin >> t;
            if(t == 0) v = lc[u];
            if(t == 2) v = rc[u];
            if(t == 1) {
                cout <<"? " << fa[u] << " " << lc[u] <<endl;
                int tt; cin >> tt;
                if(tt == 1){
                    Ans = u;
                    return;
                }
                v = fa[u];
            }
            rt = 0; root(root, v, 0, siz[v]);
            self(self, rt);
        }
        if(num == 2){
            int x, y; x = y = 0 ;
            for(auto v:to[u])
                if(!vis[v])
                    if(!x) x = v;
                    else y = v;
            cout <<"? " << x << " " << y <<endl;
            int t, v; cin >> t;
            if(t == 0) v = x;
            if(t == 2) v = y;
            if(t == 1){
                Ans = u;
                return;
            }
            rt = 0; root(root, v, 0, siz[v]);
            self(self, rt);
        }
        if(num == 1){
            int x = 0;
            for(auto v:to[u])
                if(!vis[v]) x = v;
            cout <<"? " << u << " " << x <<endl;
            int t, v; cin >> t;
            if(t == 0){
                Ans = u;
                return;
            }
            if(t == 2){
                Ans = x;
                return;
            }
            cout <<"Error\n";
            return;
        }
        if(num == 0){
            Ans = u;
            return;
        }
    };
    mx[0]=n; root(root, 1, 0, n); dfs(dfs, rt);
    cout <<"! " << Ans <<endl;
    return 0;
}
int main()
{
    std::cin.tie(0);
    std::cin.sync_with_stdio(0);
    int t=1;
    std::cin>>t;
    while(t--)
        work();
    return 0;
}