#include<bits/stdc++.h>
using namespace std;
#define inf 0x3f3f3f3f
 
int x;

inline int query(int a,int b){
    cout<<"? "<<a<<" "<<b<<endl;
    cin>>x;
    return x;
}

int n;

inline void solve(){
    cin>>n;

    vector<vector<int> >g(n+1);
    for(int i=1;i<=n;i++){
        int a,b;
        cin>>a>>b;
        if(a)g[i].push_back(a),g[a].push_back(i);
        if(b)g[i].push_back(b),g[b].push_back(i);
    }

    vector<int>mx(n+1),sz(n+1),f(n+1);
    mx[0]=inf;

    int sum=n,rt=0;

    auto find=[&](auto self,int u,int fa)->void {
        sz[u]=1,mx[u]=0;
        for(auto t:g[u]){
            if(t==fa||f[t])continue;
            self(self,t,u);
            sz[u]+=sz[t];
            mx[u]=max(mx[u],sz[t]);
        }
        mx[u]=max(mx[u],sum-sz[u]);
        if(mx[u]<mx[rt])rt=u;
    };
    find(find,1,-1);

    auto dfs=[&](auto self,int u,int fa)->void {
        sz[u]=1;
        for(auto t:g[u]){
            if(t==fa||f[t])continue;
            self(self,t,u);
            sz[u]+=sz[t];
        }
    };

    int ans=-1;

    auto wk=[&](auto self,int u)->void {
        dfs(dfs,u,-1);
        
        int son=-1,cnt=0;
        for(auto t:g[u]){
            if(f[t])continue;
            cnt++;

            if(son==-1||sz[t]>sz[son])son=t;
        }

        if(son==-1){
            ans=u;
            return;
        }

        int x=query(son,u);

        if(x==0){
            if(sz[son]==1){
                ans=son;
                return;
            }

            f[u]=1;
            sum=sz[son],rt=0;
            find(find,son,-1);
            self(self,rt);
        }else{
            if(cnt==1){
                ans=u;
                return;
            }else if(cnt==2){
                f[son]=1;
                sum=sz[g[u][g[u][1]==son]]+1,rt=0;
                find(find,u,-1);
                self(self,rt);
            }else{
                int ls=(g[u][0]==son?g[u][1]:g[u][0]);
                int rs=(g[u][0]==ls?(g[u][1]==son?g[u][2]:g[u][1]):g[u][2]);
                int x=query(ls,rs);

                if(x==0){
                    f[u]=1;
                    sum=sz[ls],rt=0;
                    find(find,ls,-1);
                    self(self,rt);
                }else if(x==2){
                    f[u]=1;
                    sum=sz[rs],rt=0;
                    find(find,rs,-1);
                    self(self,rt);
                }else{
                    ans=u;
                    return;
                }
            }
        }
    };
    wk(wk,rt);

    cout<<"! "<<ans<<endl;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);

    // cout<<setiosflags(ios::fixed)<<setprecision(10);

    int t=1;
    cin>>t;
    while(t--)solve();

    return 0;
}