#include <bits/stdc++.h>
using namespace std;
int n;
const int maxn=1e5+4;
vector<int> G[maxn];
int rt,sz[maxn],rtv;
bool used[maxn];
int cnt;
void dfs(int p,int fa)
{
    sz[p]=1;
    int t=1e9;
    for(auto v:G[p])
    {
        if(v==fa||used[v]) continue;
        dfs(v,p);
        sz[p]+=sz[v];
        t=min(t,sz[v]);
    }
    if(t<rtv||(!rt))  rt=p,rtv=t;
}
int ans;
int ask(int u,int v)
{
    assert(cnt);
    cnt--;
    cout<<"? "<<u<<" "<<v<<endl;
    cout.flush();
    int x; cin>>x; 
    if(x==-1) exit(0);
    return x;
}
void calc(int p)
{
    dfs(p,p); 
    if(sz[p]==1) {ans=p; return ;}
    int t1=0,t2=0;
    for(auto x:G[p])
    {
        if(!used[x]) 
        {
            if(!t1) t1=x;
            else t2=x;
        }
    }
    if(!t1) 
    {
        ans=p;
        return;
    }
    if(!t2) 
    {
        int t=ask(t1,p);
        if(t==0) ans=t1;
        else ans=p;
        return; 
    }
    int t=ask(t1,t2); 
    if(t==0) 
    {
        for(auto x:G[p]) 
        {
            if(x!=t1) used[x]=1;
        }
        used[p]=1;
        rt=0; sz[0]=1e9; rtv=1e9;
        dfs(t1,t1);
        dfs(rt,rt);
    }
    else if(t==2)
    {
        for(auto x:G[p]) 
        {
            if(x!=t2) used[x]=1;
        }
        used[p]=1;
        rt=0; sz[0]=1e9; rtv=1e9;
        dfs(t2,t2);
        dfs(rt,rt);
    }
    else
    {
        used[t1]=1,used[t2]=1;
        rt=0; sz[0]=1e9; rtv=1e9;
        dfs(p,p); dfs(rt,rt);
    }
    calc(rt);
}
void solve()
{
    scanf("%d",&n);
    for(int i=1;i<=n;i++) G[i].resize(0),used[i]=0;
    cnt=log2(n);
    for(int i=1;i<=n;i++)
    {
        int x,y; cin>>x>>y;
        if(x) G[x].push_back(i),G[i].push_back(x);    
        if(y) G[y].push_back(i),G[i].push_back(y);    
    }
    rt=0; sz[0]=1e9; rtv=1e9;
    dfs(1,1); dfs(rt,rt);
    calc(rt);
    cout<<"! "<<ans<<endl;
}
int main()
{
    int T; cin>>T;
    while(T--) solve();        
}
/*
2
5
0 0 
1 5
2 4
0 0 
0 0
*/