#include <iostream>
#include <vector>
#include <map>

using namespace std;
vector<int>adj[200005];
int c1=0,c2=0,sol=0,n;
int fre[100005];
int fiust[100005];
int fiudr[100005];
int par[100005];
int sub[100005];
int inf=1e6;
void dfs(int curr,int parent)
{
    sub[curr]=1;
    par[curr]=parent;
    fiust[curr]=0;
    fiudr[curr]=0;
    for(auto k:adj[curr])
    {
        if(k!=parent && fre[k]==0)
        {
            dfs(k,curr);
            sub[curr]+=sub[k];
            if(fiust[curr]==0)
            {
                fiust[curr]=k;
            }
            else
            {
                fiudr[curr]=k;
            }
        }
    }
}
int dist[100005][2];
void getdist(int curr,int par,int d)
{
    for(auto k:adj[curr])
    {
        if(k!=par)
        {
            dist[k][d]=dist[curr][d]+1;
            getdist(k,curr,d);
        }
    }
}
void taie(int a,int b)
{
    int rez;
    dist[a][0]=0;
    dist[b][1]=0;
    getdist(a,0,0);
    getdist(b,0,1);
    cout<<"? "<<a<<" "<<b<<endl;
    cin>>rez;
    if(rez==0)
    {
        for(int i=1;i<=n;i++)
        {
            if(dist[i][0]>=dist[i][1])
            {
                fre[i]=1;
            }
        }
    }
    else if (rez==1)
    {
        for(int i=1;i<=n;i++)
        {
            if(dist[i][0]!=dist[i][1])
            {
                fre[i]=1;
            }
        }
    }
    else
    {
        for(int i=1;i<=n;i++)
        {
            if(dist[i][0]<=dist[i][1])
            {
                fre[i]=1;
            }
        }
    }

}
int findbest()
{
    int i,root=0,tot,a,b,maxim;
    for(i=1;i<=n;i++)
    {
        int vec=0;
        for(auto k:adj[i])
        {
            if(fre[k]==0)
            {
                vec++;
            }
        }
        if(fre[i]==0 && vec<=1)
        {
            root=i;
        }
    }
    par[root]=0;
    dfs(root,0);
    if(sub[root]==1)
    {
        cout<<"! "<<root<<endl;
        return 1;
    }
    tot=sub[root];
    int nod1=0,nod2=0,best=tot+1;
    for(i=1;i<=n;i++)
    {
        if(fre[i]==0 && fre[fiust[i]]==0 && fre[fiudr[i]]==0)
        {
            a=fiust[i];
            b=fiudr[i];
            maxim=max(tot-sub[a]-sub[b],max(sub[a],sub[b]));
            if(maxim<best)
            {
                nod1=a;
                nod2=b;
                best=maxim;
            }
        }
        if(fre[i]==0 && fre[par[i]]==0)
        {
            a=i;
            b=par[i];
            maxim=max(sub[i],tot-sub[i]);
            if(maxim<best)
            {
                nod1=a;
                nod2=b;
                best=maxim;
            }
        }
        if(fre[i]==0 && fre[par[par[i]]]==0)
        {
            a=i;
            b=par[par[i]];
            maxim=max(max(sub[i],tot-sub[par[i]]),sub[par[i]]-sub[i]);
            if(maxim<best)
            {
                nod1=a;
                nod2=b;
                best=maxim;
            }
        }
    }
    taie(nod1,nod2);
    return 0;
}
int main()
{
    int i,j,k,l,t,op,m,a,b,xx;
    //ios_base::sync_with_stdio(false);
    //cin.tie(NULL);
    cin>>t;
    for(op=1; op<=t; op++)
    {
        cin>>n;
        for(i=1; i<=n; i++)
        {
            fre[i]=0;
        }
        fre[0]=1;
        for(i=1; i<=n; i++)
        {
            cin>>a>>b;
            if(a!=0)
            {
                adj[i].push_back(a);
                adj[a].push_back(i);
                fiust[i]=a;
                par[a]=i;
            }
            if(b!=0)
            {
                adj[i].push_back(b);
                adj[b].push_back(i);
                fiudr[i]=b;
                par[b]=i;
            }
        }
        int plm=0;
        while(findbest()==0)
        {
            plm++;
        }
        for(i=1;i<=n;i++)
        {
            adj[i].clear();
            fiudr[i]=0;
            fiust[i]=0;
            par[i]=0;
            fre[i]=0;
        }
    }
    return 0;
}