#include<bits/stdc++.h>

#define ll  long long
#define ull unsigned long long
#define ld long double
#define pii pair<ll,ll>
using namespace std;
#pragma GCC optimize(3)
#define N 600005
int cnt[N],fa[N],book[N],tot;
vector<ll> e[N];
void dfs(ll p)
{
    cnt[p]=1;
    book[p]=tot;
    for(int i=0;i<e[p].size();i++)
    {
        if(book[e[p][i]]!=tot)
        {
            dfs(e[p][i]);
            cnt[p] += cnt[e[p][i]];
        }
    }
    if(e[p].size()>=2&&cnt[e[p][0]]<cnt[e[p][1]])
    {
        swap(e[p][0],e[p][1]);
    }
}
void solve(ll root,ll n)
{
  //  cerr<<n<<endl;
    fa[root]=0;
    if(n==1)
    {
        cout<<"! "<<root<<endl;
        cout.flush();
        return;
    }
    if(n==2)
    {
        cout<<"? "<<root<<' '<<e[root][0]<<endl;
        cout.flush();
        ll op;
        cin>>op;
        if(op==0)
        {
            cout<<"! "<<root<<endl;
            cout.flush();
        }
        else
        {
            cout<<"! "<<e[root][0]<<endl;
            cout.flush();
        }
        return;
    }
    ll p=root;
    while(cnt[e[p][0]]>n/2) p=e[p][0];
    if(e[p].size()<2||(fa[p]&&n-cnt[p]>cnt[e[p][1]]))
    {
        cout<<"? "<<fa[p]<<' '<<e[p][0]<<endl;
        cout.flush();
        ll op;
        cin>>op;
        if(op==0)
        {
            ll tt=cnt[p],pos=fa[p];
            while(pos)
            {
                cnt[pos]-=tt;
                pos=fa[pos];
            }
            if(e[fa[p]].size()>1)
            {
                e[fa[p]][0]=e[fa[p]][1];
            }
            e[fa[p]].pop_back();
            solve(root,cnt[root]);
        }
        else if(op==1)
        {
            cnt[p]-=cnt[e[p][0]];
            if(e[p].size()>1)
            {
                e[p][0]=e[p][1];
            }
            e[p].pop_back();
            solve(p,cnt[p]);
        }
        else
        {
            solve(e[p][0],cnt[e[p][0]]);
        }
    }
    else
    {
        cout<<"? "<<e[p][0]<<' '<<e[p][1]<<endl;
        cout.flush();
        ll op=0;
        cin>>op;
        if(op==0)
        {
            solve(e[p][0],cnt[e[p][0]]);
        }
        else if(op==1)
        {
            cout<<"! "<<p<<endl;
            cout.flush();
            return;
        }
        else
        {
            solve(e[p][1],cnt[e[p][1]]);
        }
    }
}

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    // freopen("")
    int T;
    cin>>T;
    while(T--)
    {
        ll n;
        cin>>n;

        for(int i=1;i<=n;i++)
        {
            ll x,y;
            cin>>x>>y;
            if(x) { e[i].push_back(x);fa[x]=i; }
            if(y) { e[i].push_back(y);fa[y]=i; }
        }
        ll root=1;
        for(int i=1;i<=n;i++)
        {
            if(!fa[i])
            {
                root=i;
                ++tot;
                dfs(i);
                break;
            }
        }
        solve(root,n);
        for(int i=0;i<=n;i++)
        {
            e[i].clear();
            cnt[i]=0;
            fa[i]=0;
        }
    }
    return 0;
}