#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define endl '\n'


int ask(int u,int v)
{
    
    cout<<"? "<<u<<" "<<v<<endl;
    int t;
    cin>>t;
    return t;
}
int n,st,ed;
int L[100010],R[100010],in[100010];
void dfs(int u)
{
    if(L[u]&&R[u])
    {
        int t=ask(L[u],R[u]);
        if(t==1) 
        {
            ed=u;
            return ;
        }
        else if(t==0) dfs(L[u]);
        else dfs(R[u]);
    }
    else if(L[u]||R[u])
    {
        if(L[u]) dfs(L[u]);
        else dfs(R[u]);
    }
    else 
    {
        ed=u;
        return ;
    }
}
int fa[100010];
void solve()
{    
    cin>>n;
    for(int i=1;i<=n;i++) in[i]=fa[i]=0;
    for(int i=1;i<=n;i++)
    {
        cin>>L[i]>>R[i];
        fa[L[i]]=i;
        fa[R[i]]=i;
        in[L[i]]++;
        in[R[i]]++;
    }
    int root;
    for(int i=1;i<=n;i++) 
    if(!in[i])
    {
        root=i;
        break;
    }
    
    ed=0;
    dfs(root);
    
    vector<int>path;
    path.push_back(ed);
    while(!L[fa[ed]]||!R[fa[ed]])
    {
        ed=fa[ed];
        if(ed==0) break;
        path.push_back(ed);
    }
    
    if(path.size()==1) cout<<"! "<<path[0]<<"\n";
    else
    {
        
        int l=0,r=path.size()-1;
     
        while(1)
        {
            int t=ask(path[l],path[r]);
            if(t==1)
            {
                cout<<"! "<<path[(l+r)/2]<<"\n";
                return ;
            }
            else if(t==0) 
            {

                int len=r-l+1;
                if(len&1)
                {
                    r=l+len/2-1;
                }
                else
                {
                    r=l+len/2-1;
                }

            }
            else 
            {
                int len=r-l+1;
                if(len&1)
                {
                    l=r-len/2+1;
                }
                else
                {
                    l=r-len/2+1;
                }
            }
            if(l==r) break;
        }
        cout<<"! "<<path[l]<<"\n";
    }
}

int main (){
    ios::sync_with_stdio(0);
    // cin.tie(0);
    // cout.tie(0);
    cout.flush();
    int t=1;
    cin>>t;
    while(t--){
        solve();
    }
    
    return 0;
}