#include<bits/stdc++.h>
#define int long long
// #define endl '\n'
using namespace std;
int ask(int x,int y)
{
    cout<<"? "<<x<<' '<<y<<endl;
    int res;cin>>res;
    return res;
}
void solve()
{
    int n;cin>>n;
    set<int> e[n+1];
    for(int i=1;i<=n;i++)
    {
        int v1,v2;
        cin>>v1>>v2;
        if(v1) e[i].insert(v1),e[v1].insert(i);
        if(v2) e[i].insert(v2),e[v2].insert(i);
    }


    vector<int> dep(n+1);
    vector<int> fa(n+1);
    function<void(int,int)> dfs=[&](int u,int f)
    {
        dep[u]=dep[f]+1;
        fa[u]=f;
        for(auto v:e[u])
        {
            if(v==f) continue;
            dfs(v,u);
        }
    };
    int l=1,r,maxn=0,times=0;
    while(times<log2(n))
    {
        fill(dep.begin(),dep.end(),0);
        fill(fa.begin(),fa.end(),0);
        maxn=0;
        dfs(l,0);
        for(int i=1;i<=n;i++)
        {
            if(dep[i]>maxn)
            {
                maxn=dep[i];
                l=i;
            }
        }
        fill(dep.begin(),dep.end(),0);
        fill(fa.begin(),fa.end(),0);
        // for(int i=1;i<=n;i++) cout<<dep[i]<<' ';
        // cout<<l<<endl;
        dfs(l,0);
        // for(int i=0;i<=n;i++) cout<<dep[i]<<' ';
        // cout<<endl;
        maxn=0;
        // cerr<<"============\n";
        for(int i=1;i<=n;i++)
        {
            // cout<<maxn<<' '<<dep[i]<<endl;
            if(maxn<dep[i])
            {
                maxn=dep[i];
                r=i;
            }
        }
        // cout<<l<<' '<<r<<endl;
        vector<int> tmp;
        for(int i=r;;i=fa[i])
        {
            tmp.push_back(i);
            if(i==l) break;
        }
        reverse(tmp.begin(),tmp.end());
        // for(auto x:tmp) cout<<x<<' ';
        // cout<<endl;
        if(l==r){cout<<"! "<<l<<endl;return;}
        int op=ask(l,r);
        if(op==0)
        {
            int mid=tmp.size()/2-1;
            // cout<<mid<<endl;
            if(mid+1<tmp.size() && mid>=0 && mid<tmp.size())e[tmp[mid]].erase(tmp[mid+1]);
        }
        if(op==1)
        {
            int mid=tmp.size()/2;
            if(mid+1<tmp.size() && mid>=0 && mid<tmp.size())e[tmp[mid]].erase(tmp[mid+1]);
            if(mid-1>=0 && mid>=0 && mid<tmp.size())e[tmp[mid]].erase(tmp[mid-1]);
            l=tmp[mid];
        }
        if(op==2)
        {
            int mid=(tmp.size()+1)/2;
            // cout<<mid<<endl;
            // cout<<tmp[mid]<<endl;
            if(mid-1>=0 && mid>=0 && mid<tmp.size())e[tmp[mid]].erase(tmp[mid-1]);
            // cout<<*lower_bound(e[tmp[mid]].begin(),e[tmp[mid]].end(),tmp[mid-1])<<endl;
            // for(auto v:e[2]) cout<<v<<' ';
            // cout<<endl;
            l=r;
            // cout<<"l:"<<l<<endl;
        }
        times++;
    }
    cout<<"! "<<l<<endl;
}
signed main()
{
    cin.tie(0)->sync_with_stdio(0);
    int t=1;
    cin>>t;
    while(t--) solve();
    return 0;
}