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

const int N = 2e5 + 10;
const ll mod = 1e9 + 7;
const ll INF = 1e18;

ll n,m;
vector<ll>ve[N];
set<ll>trees;
int cen[5];
int cenpos;
ll dp[N][5],sum[N],minn[N],num;
void dfs(ll u,ll fa){
    dp[u][0]=dp[u][1]=0;
    sum[u]=1;
    minn[u]=0;
    int cur=0;
    for(auto e:ve[u]){
        if(e==fa)continue;
        dfs(e,u);
        dp[u][cur++]=sum[e];
        sum[u]+=sum[e];
    }
    for(int i=0;i<cur;i++){
        minn[u]=max(minn[u],dp[u][i]);
    }
    minn[u]=max(minn[u],num-sum[u]);
}
int ask(int u,int v){
    cout<<"? "<<u<<' '<<v<<endl;
    cout.flush();
    int tag;cin>>tag;
    return tag;
}
void inidfs(int u,int fa){
    trees.insert(u);
    for(auto e:ve[u]){
        if(e==fa)continue;
        inidfs(e,u);
    }
}
void init(int u){
    trees.clear();
    inidfs(u,0);
}
ll dfs1(int u,int fa){
    ll res=1;
    for(auto e:ve[u]){
        if(e==fa)continue;
        res+=dfs1(e,u);
    }
    return res;
}
void solve()
{
    cin>>n;
    trees.clear();
    for(int i=1;i<=n;i++)ve[i].clear(),trees.insert(i);
    for(int i=1;i<=n;i++){
        int x,y;cin>>x>>y;
        if(x){
            ve[i].push_back(x);
            ve[x].push_back(i);
        }
        if(y){
            ve[i].push_back(y);
            ve[y].push_back(i);
        }
    }
    while(trees.size()>1){//logn
        int root=*trees.begin();
        num=trees.size();
        cenpos=0;
        dfs(root,0);
        ll tmpmin=INF;
        for(auto e:trees){
            tmpmin=min(tmpmin,minn[e]);
        }
        for(auto e:trees){
            if(minn[e]==tmpmin){
                cen[cenpos++]=e;
            }
        }
        if(cenpos==1){
            int center=cen[0];
            int lcen,rcen;
            if(ve[center].size()==2){
                lcen=ve[center][0];
                rcen=ve[center][1];
            }
            else if(ve[center].size()==1){
                lcen=ve[center][0];
                rcen=center;
            }
            else{////////////////////////////
                priority_queue<pll>pq;
                for(auto e:ve[center]){
                    pq.push({dfs1(e,center),e});
                }
                lcen=pq.top().second;
                pq.pop();
                rcen=pq.top().second;
            }
            int tag=ask(lcen,rcen);
            if(tag==0){
                auto p=ve[lcen].begin();
                for(;p!=ve[lcen].end();p++){
                    if(*p==center){
                        ve[lcen].erase(p);
                        break;
                    }
                }
                init(lcen);
            }
            else if(tag==1){
                auto p=ve[center].begin();
                for(;p!=ve[center].end();p++){
                    if(*p==lcen){
                        ve[center].erase(p);
                        break;
                    }
                }
                for(p=ve[center].begin();p!=ve[center].end();p++){
                    if(*p==rcen){
                        ve[center].erase(p);
                        break;
                    }
                }
                init(center);
            }
            else{
                auto p=ve[rcen].begin();
                if(center==rcen)center=lcen;
                for(;p!=ve[rcen].end();p++){
                    if(*p==center){
                        ve[rcen].erase(p);
                        break;
                    }
                }
                init(rcen);
            }
        }
        else{
            int tag=ask(cen[0],cen[1]);
            if(tag==0){
                auto p=ve[cen[0]].begin();
                for(;p!=ve[cen[0]].end();p++){
                    if(*p==cen[1]){
                        ve[cen[0]].erase(p);
                        break;
                    }
                }
                init(cen[0]);
            }
            else{
                auto p=ve[cen[1]].begin();
                for(;p!=ve[cen[1]].end();p++){
                    if(*p==cen[0]){
                        ve[cen[1]].erase(p);
                        break;
                    }
                }
                init(cen[1]);
            }
        }
    }
    cout<<"! "<<*trees.begin()<<endl;
    cout.flush();
}
int main()
{
    // ios::sync_with_stdio(false);
    // cin.tie(0);
    ll _ = 1;
    cin >> _;
    // cin.get();
    while (_--)
    {
        solve();
    }
    return 0;
}